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EXPERIMENTAL PSYCHOLOGY 

AND ITS BEARING UPON 
CULTURE 



•*&&& 



Experimental Psychology 

AND ITS BEARING UPON 
CULTURE 



BY 



GEORGE MALCOLM STRATTON 

M.A., Yale; Ph.D., Leipzig 

ASSOCIATE PROFESSOR OF PSYCHOLOGY AND DIRECTOR OF THE PSYCHOLOGICAL 
LABORATORY IN THE UNIVERSITY OF CALIFORNIA 



THE MACMILLAN COMPANY 

LONDON: MACMILLAN & CO., Ltd. 
1914 

All rights reserved 






Copyright, 1903, 
By THE MACMILLAN COMPANY. 



Set up and electrotyped. Published April, 1903. Reprinted 
February, 1908; March, 1914. 






Norfoootr $«ss 

J. S. Cushing Co. —Berwick & Smith Co. 

Norwood, Mass., U.S.A. 



PREFACE 

The aim of the present volume is to give an un- 
technical account of certain groups of experiments 
in psychology and to show something of their signifi- 
cance. As to the particular experiments that are of 
most interest and importance in this field, of course 
opinions would differ. Every one who works in 
psychology soon finds himself attracted in special 
directions, and on the whole it is perhaps well for a 
writer to respect this element of personal affinity. 
But in preparing the book, I have aimed to present, 
as best I could within somewhat narrow limits, the 
character and value of the laboratory psychology, 
especially as bearing upon our moral and philosoph- 
ical interests. In this way the book is planned to 
occupy a different field from that already so well 
covered by the excellent works of Titchener, San- 
ford, and Scripture. 

Considerable attention has thus been given to the 
interpretation of the experimental results, — to their 
more immediate scientific meaning, as well as to 
what they suggest for life and for speculation. But 
first and foremost the purpose has been to get the 
experiments themselves clearly before the reader, so 
that the main features of the research work might 



vi Preface 

be seen concretely. Many of the experiments thus 
described are already familiar to students of psy- 
chology, but a number appear here for the first time. 
It would be difficult, if not impossible, to tell in 
detail of my obligation to others. I cannot forbear 
to mention, however, the Council and members of the 
Philosophical Union of the University of California, 
who some years ago invited me to speak to them 
upon the character and import of psychological ex- 
periments, and to whose interest and encouragement 
the present volume largely owes its existence. I am 
also particularly grateful to my friend, Professor 
Bakewell, who has kindly read the book in proof, 
and has given me throughout most helpful advice. 
In preparing the chapters dealing with the psy- 
chology of ^Esthetics I have received great benefit 
from the criticism of my friend, Mr. Frederic C. 
Torrey, and I am indebted to my colleague, Dr. Mon- 
tague, for similar aid in regard to certain problems of 
Space. For the photographs required in many of 
the illustrations I must thank Mr. Brand, the former 
Assistant in the Laboratory, and Mr. Dunlap, the 
present Assistant. There is a more general indebted- 
ness to my honored teacher, Professor Wundt of 
Leipzig, who introduced me to the experimental 
work. But I owe most of all to my teacher and 
friend, Professor Howison, to whom I should have 
been glad to dedicate affectionately this book were 
I not so fully conscious of its shortcomings. 



CONTENTS 



I. Historical Introduction 

II. The General Character of Psychological Experiments 

III. The Possibility of Mental Measurements 

IV. The Evidence for Unconscious Ideas 
V. Further Considerations as to the Unconscious 

VI. Illusions and their Significance 

VII. Experiments on Mental Space, particularly the Space 

of the Blind 

VIII. The Harmonies and Discords of Space Perception, 
and its Place in Experience .... 

IX. Memory and the Influence of Time 

X. Temporal Signs and the Rank of Memory 

XI. Imitation and Suggestion 

XII. The Enjoyment of Sensations and their Forms 

XIII. Color and the Differentiation of the Fine Arts 

XIV. The Connection of Mind and Body 

XV. Spiritual Implications of the Experimental Work 

Index 



i 

17 
33 
66 
82 
95 

122 

142 
165 
185 
199 
227 
249 
262 
295 

315 



vu 



CHAPTER I 
HISTORICAL INTRODUCTION 

Only within a few years has it been generally The roots 
known that experiments on the mind were being Uj^pj-y. 
attempted. Doubtless the whole subject has still for choiogy." 
some an air of novelty and perhaps almost of fad- 
dishness, as if it had sprung into life but yesterday 
and would pass away to-morrow. But the fact is, 
that like so many things that suddenly catch the 
public eye, the days of its growth have been long 
and quiet, and the suddenness is not of its appear- 
ance but only of noising its fame abroad. For just 
as Darwinism was germinating in the days of Hera- 
clitus, so we can now discover the premonitions of 
what is often called the " New Psychology " at least 
as early as Aristotle. He performed experiments in 
psychology, and ever since his time traces of such 
work can be found. The modern turn, then, is not 
in discovering the possibility of psychological experi- 
ments, but in becoming distinctly conscious of their 
value, — in utilizing them, therefore, to a greater 
extent and in developing something like a critical 
procedure in carrying them out. 

To understand the motives that have led to the Reasons for 
laboratory work in psychology one must recall that lts s rowth - 
for centuries the peculiar and solitary method of 



2 Experimental Psychology- 

getting at the facts of mind was supposed to be that 
of self-observation, or of introspection, as it is more 
frequently called. Whether we recognize the method 
by name or not, it certainly is one with which all are 
familiar. You can probably tell, for instance, whether 
the thought of territorial expansion beyond the seas 
meets your approval, or whether you view it with 
mingled consent and distrust, or perhaps with un- 
mixed regret. This direct acquaintance with the 
state of our minds which all of us to some extent pos- 
sess, is the essence of introspection, and, as I have 
said, was for centuries the only recognized mode of 
collecting the data of psychology. The psychologist 
turned his mental gaze inward, and reported as best 
he could what he there observed. The objects of 
this science were supposed to be noted by some inner 
sense, in contrast with our eyes and ears, with which 
we observe external objects, the materials for the 
familiar natural sciences. 
Difficulties Now it can be pretty clearly shown that self- 

tion? tr ° SpeC " observation must always be the fundamental method 
of psychology ; it permits the initial step and fur- 
nishes us with all the really first-hand knowledge of 
the mental world that we possess. But for all that, 
one must not fail to recognize the historical fact that 
psychology, as long as it relied solely on this method, 
was at a striking disadvantage compared with the 
natural sciences generally. In the first place, the 
posture of introspection is cramped and unnatural. 
We are practical beings and, if we are healthy, life 
has trained us to be interested in things beyond our- 
selves. The habit of self-observation, if not a morbid 



Historical Introduction 3 

trait, as in Amiel or Marie Bashkirtseff, is at least 
artificial, and tends to throw the whole mental train 
off the track. Try, for instance, to be deeply inter- 
ested in what some one is saying to you, and at the 
same time to scrutinize and report to yourself how 
it feels to be deeply interested. Many of our most 
important mental states positively refuse to be gazed 
at in this way; they elude our direct scrutiny, and 
the best we can do is — paradoxical as it sounds — 
to recall how they looked when we were not looking at 
them. 1 Compared with those sciences whose materials 
are absolutely indifferent to any amount of weighing 
and grinding and heating and examination, one can 
well understand how the progress of psychology was 
inevitably slow and, to some extent, disappointing. 
Moreover, there is something peculiarly private and 
incommunicable in every fact of mind. We cannot, as 
a mineralogist may, hand around our particular speci- 

1 This fugitive character of many of our mental states has often 
been pointed to in proof of the impossibility of introspection. The 
truth of course is, that only by means of introspection do we know that 
our mental processes are changeable and elusive. It is curious that 
when critics like Maudsley, at least in his earlier writings, make such 
short work of self-observation as a psychological method, they do not 
see that most of the facts they bring forth as evidence of its funda- 
mental inadequacy are obtained only by this very self-observation. 
They trust their own introspection in its report that the mental life is 
always in flux, that attention to our mental processes alters their char- 
acter, etc., and then argue that this discredits the whole procedure ; 
whereas these very results show that the method, within certain limits, 
is the readiest and most reliable we have. 

Such criticisms also invariably dwell on those mental processes (the 
emotions, for instance) that are most liable to interruption if we attend 
to them, and cannot well be repeated at will, and leave out of account the 
many processes, such as perceptions and judgments and certain memory- 
images, that can be repeated and observed with great security. 



Experimental Psychology 



Desire for 

"objective" 

methods. 



men of judgment or volition, and ask others to verify 
the results of our examination of it. The results of 
self-observation consequently seem to be personal and 
"subjective," and lacking in that universality which 
is the pride of chemistry and of physics. It was to 
be expected, then, that there would be a longing for 
some mode of investigation wider in its application 
and more fruitful than self -observation, and that in 
due time there would be an organized revolt in favor 
of " objective " methods, among which the experimen- 
tal procedure was to have an important place. 



Influence of 
British 
empiricism. 
Bacon to 
Hume. 



Berkeley's 

psychology 
of space. 



The present-day experimental study of mind is but 
the latest development of that scientific movement 
of which Francis Bacon was chief spokesman. Bacon 
led to Hobbes, with whom there began the strong 
empirical movement in psychology in the seventeenth 
and eighteenth centuries, to which our present meth- 
ods of investigating the mind owe so much. The 
English were the first to become interested in psy- 
chology for its own sake. On the continent it had 
always been a secondary matter, a mere appendage 
to metaphysics ; whereas the English, in Locke and 
Berkeley and Hume, almost reversed the order and 
made metaphysics a subordinate chapter of psy- 
chology. At any rate, the facts of our everyday 
mental life at last came to their own, and in the 
writers just mentioned some of the chief problems 
of the experimental work began to be mapped out. 
Berkeley's remarkable " Essay toward a New Theory 
of Vision " shows a distinctly modern attitude toward 
psychology, which at that day it would indeed be difri- 



Historical Introduction 5 

cult to parallel. He states the particular question, 
how we are able to discern by sight the size and dis- 
tance and shape of objects ; and after a masterly array 
of facts and arguments, comes to his well-known con- 
clusion that none of these aspects of things is given 
us by vision alone and of itself, but only by vision in 
conjunction with our sense of touch. Not until we 
are able to translate our impressions of sight into 
terms of touch and muscular movement, does our 
vision come to mean for us anything spatial. If 
history had been as silent in regard to the life and 
time of Berkeley as it is about the personality of 
Shakespeare, not only his theory but also the man- 
ner in which he supports it might have given excel- 
lent grounds for some clever critic to claim that the 
good bishop had merely lent his name to the produc- 
tion of some shy disciple of Helmholtz or of Wundt. 
So far as I am aware, Berkeley gives the first instance 
of a problem of psychology being thus disentangled 
and honored with a special and purely psychological 
treatise. 

As if to furnish the experimental verification which Surgeons' 
Berkeley himself recognized was needed for his theory, J^JJ ™f s nts 
there soon appeared the first of a series of contribu- view, 
tions by various physicians in the "Philosophical 
Transactions of the Royal Society of London," giv- 
ing the results of experiments on persons operated 
upon for congenital cataract. The most celebrated 
case was that reported by Cheselden in 1728, and 
this was followed by others from Home, Ware, 
Wardrop, and many besides. If Berkeley's theory 
were correct, then a person gaining his sight sud- 



6 Experimental Psychology 

denly, as these patients for the most part did, 
ought not to be able to discern the shape or dis- 
tance or direction of objects by sight alone, but 
only by sight working in combination with touch. 
A number of tests were accordingly made, the de- 
tailed discussion of which will come more appro- 
priately in a later chapter. Here it is sufficient to 
say that the results have generally been considered 
as strongly in favor of Berkeley's theory; but this 
interpretation is, I think, open to question, and needs 
a careful review. The interesting fact in the present 
connection, however, is not whether the evidence he 
offered is adequate or inadequate, but that Berkeley 
and a large body of men recognized in this practical 
way that there were important psychological problems 
which were to be decided, not by the traditional in- 
trospective method, but by external and experimental 
means. 
Place of the We may pass by the later English development in 
a^sodation- Hart l e Y> J am es Mill, John Stuart Mill, and Spencer. It 
ists. is of great importance for the history of psychology 

in general, but not for the growth of the experimental 
side. These men were system-makers, interested 
most of all in working out what seemed to them to 
be the one great explanatory principle in psychology, 
— the principle of association. It is well that there 
are such men, who feel that the subordinate questions 
of a subject are to be answered by learning the com- 
mon secret of the whole. But experimental psy- 
chology is indebted perhaps more to those whose 
interests run to the opposite pole, — who feel that 
the search for the secret of the whole may be de- 



Historical Introduction 7 

ferred until we know more about the subordinate 
parts of that whole. Wisdom is doubtless justified 
of both kinds of children. But it is easy to see that 
when the English psychological activity turned more 
and more to buttressing up a system, the atmosphere 
there grew less stimulating for the other kind of work. 
Germany, on the other hand, was running exactly the TheGer- 
opposite course. The Germans, after their long line mans wear x 
of philosophers from Leibnitz to Hegel, were at last physics, 
coming to the point which England and France had 
reached long before, — were losing faith in philosophy 
altogether, and were preparing to attack the problems 
of mind from the other side. 

But in Germany, as in England, the interest in the 
experimental study of consciousness was not developed 
entirely from within the ranks of the psychologists 
themselves. Goethe, for instance, was among the Goethe's ex- 
early experimenters in psychology. He made an J^to™olor 
interesting study of the influence of color upon the 
emotions, by observing the landscape through glasses 
now of one color and now of another, and noting the 
contrasting moods induced by the different hues. 1 
And some experiments which bear a much closer Psychoiog- 
connection with the direct historical development lcal «xpen- 

r ments by 

came indeed from the astronomers, brought about, astronomers, 
of course, not by any special interest in psychology, 
but by the practical needs of their observatory work. 
According to the older method of determining 
the time when a star reached its meridian, the ob- 
server watched the passage of the star through the 
field of his telescope, and at the same time listened 

1 Farbenlehre, §§ 769, 784, 798. 



8 



Experimental Psychology 



Determina- 
tion of "per- 
sonal equa- 
tion." 



Influence of 

the physiolo- 



to the beats of a clock near at hand. As the criti- 
cal moment approached, he had now to perform the 
somewhat difficult task of noting at what instant in 
the series of pendulum beats the passage of the star 
across the meridian (marked by a hair-line in the 
field of the telescope) actually occurred. To do this 
accurately he must tell not merely at which beat of 
the clock this transit took place, but since the transit 
usually occurs somewhere between two beats, he must 
determine the more exact fraction of a beat which had 
elapsed when the star reached the meridian. This was 
the "eye and ear" method, now discarded, by many 
astronomers, for the chronograph with its electric 
recorders. The astronomer Bessel noticed as early 
as 1822 that when different persons observed the very 
same fact, there were discrepancies which could be 
accounted for only by the different make-up of the 
observers themselves. And experiments were accord- 
ingly instituted to determine what has since come to 
be known as " personal equation." All this was a 
psychological matter, and the experiments that gave 
some light on the question were psychological experi- 
ments, even though carried on from an interest pri- 
marily in quite a different field. Out of these has 
grown an important group of laboratory investi- 
gations in what is called reaction-time, of which 
more will be said in a later chapter. 

But the work which had a more direct influence in 
developing systematic experimentation in psychology 
came from the physiologists, especially from those 
who were interested in the sense-organs. Any one 
who will turn the pages of the particular volumes of 



Historical Introduction 9 

Hermann's " Hand-book " that are devoted to the 
subject, will see how many experiments were early- 
carried on to discover primarily the function of the 
sense-organs, but which in so doing laid bare much of 
the psychology of our sense-perception. Probably 
few besides professional students appreciate the fact 
that much of Helmholtz's labors lay on the psycho- Helmholtz's 
logical side of the border between physiology and f sy ^° " work 
psychology, and that he may be claimed for either 
science. His great works on " Physiological Optics " 
and on " Sensations of Tone " are stores of psycho- 
logical material gathered in, for the most part, through 
Helmholtz's own genius for devising and carrying out 
experiments in this field. And there were many other 
pioneers in the same region. Vierordt, for example, 
more than half a century ago, made an experimental 
study of our sense of time — a field of investigation 
since then diligently worked in the modern labora- 
tories. And almost with apologies, one ought to men- 
tion the phrenologists, Gall and Spurzheim. Unscien- phrenology 
tific as the whole spirit of these men was, their curious * nd . mode ™ 

r brain locah- 

system undoubtedly did much to stimulate those later zation. 
experiments regarding the connection between brain 
and consciousness, that led to the brilliant discoveries 
in the "localization" of mental function, with which 
the names of Broca, Goltz, Ferrier, and many others 
are connected. 1 

1 The more physiological aspects of psychology are considered at 
some length in the chapter on "The Connection of Mind and Body." 
There is an excellent sketch of the growth of this neural work by 
Dr. Henry Smith Williams in an article entitled " The Century's 
Progress in Experimental Psychology," in Harpers Magazine for 
September, 1899, Vol. 99, p. 512. 



IO 



Experimental Psychology 



The immedi- 
ate parentage 
of experi- 
mental 
psychology. 



E.H.Weber. 



Character 
of his 
experiments. 



When we try to trace out, however, not so much 
the various distant sources, but the immediate parent- 
age of experimental psychology, one must name first 
of all Ernst Heinrich Weber. With him there begins 
what we might call an unbroken experimental tradi- 
tion. Up to Weber's time (his floruit is well along 
in the second and third quarters of the nineteenth cen- 
tury), and even with many who outlived him, psycho- 
logical experiments were carried on sporadically and 
without much appreciation of their true significance. 
Weber, however, aroused an interest not only in his 
results, but even more in the experimental method 
by which his results were obtained. He made men 
recognize experimentation as a mode of procedure 
for psychology, — a recognition which since his time 
has gradually become clearer until now it is no longer 
open to doubt. So that the historical importance of 
Weber's experiments quite overshadows their in- 
trinsic interest. But his contributions so enter into 
the after-life of the subject, and in telling of his 
successors one must so often refer to Weber's Law, 
that it will perhaps be well to go somewhat into 
detail at this point, even at the risk of seeming 
prolix. 

In these experiments the more immediate purpose 
was to determine the relative sensitiveness of differ- 
ent parts of the skin, probably with some apprecia- 
tion of the value of such tests for the physician. In 
certain nervous diseases, for instance, the symptoms 
are in part a lowering or heightening of the sense of 
touch, and the character and extent of the disease 
are indicated by comparing the sensitiveness of the 



Historical Introduction n 

patient with that of a normal person. Weber arrived 
at a table of this normal sensitiveness and its varia- 
tions for different parts of the body, experimenting 
with compass points and with weights. 

But more important, judged by the amount of dis- 
cussion they set going, were his experiments on our 
power of comparing different weights on the skin. 
His tests here led him to discover an interesting bit 
of relativity. He placed a standard weight of 32 
drachms on his hand and found that an addition of 
about 10 drachms made the weight sensibly heavier. 
But when he used, instead, a standard weight of 32 
ounces (eight times heavier than the former standard) 
the same absolute addition of 10 drachms was no 
longer detected, but he must make the same relative 
addition, namely 10 ounces, before the weight was 
noticeably increased. Stated as a general proposition, 
applicable not only to weights and pressures, but to 
all our perceptions, this becomes the famous formula 
known as Weber's Law, that our power of detecting His law 
differences between sensations does not depend on °^ s n cnmi " 
the absolute amount of difference in the stimuli, but 
on its relative amount. And although some might 
believe that it did not require experiments to show 
so obvious a truth, yet later researches have demon- 
strated that it is by no means so obvious after all, 
and that there are considerable stretches of our mental 
life where, if the law does hold good, something at 
least interferes with its clear manifestation. 

One of the most important results of Weber's Fechnerand 
experiments, however, was their effect upon Fech- Sj^^f 10 " 
ner, a German scientist of philosophical bent. He Law. 



12 Experimental Psychology- 

entered with zeal upon the investigation of the prob- 
lem which Weber's studies had raised, and for years 
his daily programme included an hour or more of 
careful and accumulated tests of the validity of 
Weber's Law, by an elaborate method (and for his 
day, somewhat elaborate apparatus) largely of Fech- 
ner's own devising. Finding that the results he 
obtained by his thousands of experiments in lifting 
weights were approximately what the law would 
require, he recast Weber's statement into a mathe- 
matical formula which, in spite of its impressive loga- 
rithmic appearance, is in all probability not so near 
the actual truth as is Weber's own simpler expres- 
sion. Having satisfied the mathematical impulses 
within him, Fechner next fell to work to point out 
the philosophical consequences which his formula 
might imply. The result of his own and Weber's 
experiments seemed to him to indicate a peculiar 
interrelation of brain and mind — that the mind is, in 
some respects, more sluggish than the brain, and that 
as we increase the activity of the brain, the activity 
of the mind increases at a much slower pace., Or, to 
express his view more exactly and technically, our 
sensations vary in intensity as the logarithm of the 
brain-action which corresponds to them. 1 Because 

1 With Fechner the law took the mathematical form ■• — 

7 = k logf , 
b 

where y represents the intensity of the sensation, p the amount of the 

stimulus, b the threshold intensity, and k a constant to be determined 

experimentally for each of the senses. See his Elements der Psycho- 

physik, 2d ed., Vol. II, p. 13. 

It might be added that the essential point of Fechner's modification 



Historical Introduction 13 

Fechner believed that his modification of Weber's 
Law expressed a fundamental relation between the 
world of matter and the world of mind, his formula 
is known as the Psycho-physical Law, and experi- 
ments in this line, or even merely in verification 
of Weber's Law, are often grouped together under 
the term " psycho-physics." 

But whatever we may think of Fechner's interpre- 
tation of his results, his robust faith in experiment 
and his feeling of the bearing of such work on 
the fascinating problem of mind and brain did 
much to accelerate the movement which Weber had 
inaugurated. With his work is directly connected 
that of M idler at Gottingen, whose correspondence g. e. Mtuier. 
with Fechner over their common interests has made 
an attractive little book. At Midler's laboratory one 
may still see Fechner's contrivances for his weight 

of Weber's Law is often attributed to Weber himself, even by careful 
writers. The statement of the law, that for the sensation to increase 
in arithmetical progression the stimulus must increase in geometrical 
progression, is in the spirit of Fechner rather than of Weber. Weber 
himself apparently never went into the question of the mathematical 
relation between stimulus and sensation, and merely expressed the 
fact that in making comparisons we note the relative differences of 
things, and not their absolute differences. (See his De Pulsu, 
Resorptione, Auditu, et Tactu, Lips., 1834, p. 173; and also his 
Ueber die Lehre vom Tastsinne und Gemeingefuhle, 185 1, p. 105.) 
And even to this day the facts seem to give no especial warrant for the 
logarithmic interpretation. If the least perceptible difference may be 
psychologically a variable, — in other words, since it is perhaps ever in- 
creasing as the sensation itself increases, — what is to prevent our 
believing that stimulus and sensation increase from threshold to acme 
in practically parallel courses, rather than that the sensation increases 
at a slower rate than the stimulus, as is so often stated in the text-books 
as the obvious meaning of the psycho-physical experiments? 



14 Experimental Psychology 

experiments, and actually still in use, as I know, not 
far in the past. Other things that he used are 
treasured at the Leipzig laboratory, in what the 
assistants there humorously call the "reliquary" of 
the establishment. 

wundtand It is, in fact, at Leipzig that one next finds the 
^LeTri ma -i n line of the experimental tradition. It was there 
that the first special laboratory for psychology was 
established by Professor Wundt, — a man who has 
for many years maintained a preeminent place 
among those interested in this line of research. 
Like so many others who have contributed to the 
development of this side of psychology, Wundt began 
as a physiologist, although even in his early writings 
one can detect an interest beyond the material pro- 
cesses involved. But the philosophical and psycho- 
logical strain in the man's nature became manifest 
when in 1874 he published the first edition of 
his celebrated " Physiological Psychology," subse- 
quently many times rewritten until it now consists of 
some twelve hundred pages and more. In this work 
Wundt has gathered together the scattered mass of 
psychological material, in large part from the experi- 
ments of the physiologists, and has added the rich 
results of his own experiments and of the band of 
workers whom he has had associated with him for 
many years. In 1879 he inducted the University 
of Leipzig to set aside for him a small space for 
psychological experiments, and from this modest 
beginning has come his present laboratory of most 
impressive size and equipment. Wundt's laboratory, 



Historical Introduction 15 

moreover, is the parent stock from which a host of 
others of like kind have either directly or indirectly 
had their origin. The layman can get an impression 
of its activity from the fact that the Philosophische 
Studien y the official organ of the laboratory, has just 
closed its career after completing twenty solid vol- 
umes. Wundt himself has shown an astonishing 
power of stimulating the work and at the same time 
rendering it cautious and critical, and he will cer- 
tainly always be counted one of the great figures in 
the history of modern psychology. 

This historical sketch ought not to close without Theimpor- 
some mention of the name of Lotze, whose " Medi- J™j^° 
cinische Psychologie " (1852) is an important fore- 
runner of all our present physiological psychologies. 
The main current of the experimental stream came 
less directly through him than through Weber and 
Fechner ; but he was a man incomparably larger than 
either of them, and must certainly be acknowledged 
as one of the great forces in developing the work, — 
his mind was so rich and frank and judicial in regard 
to the larger problems of the subject, and at the same 
time so appreciative of the details and bearing of 
minute scientific research. It would be well if all 
could preserve the fine balance and interplay of exact 
observation and large ideas which Lotze always 
showed. If one were to attempt to trace the in- 
tellectual ancestry of Lotze and to account for his 
philosophical breadth along with the sincere sym- 
pathy for the newer methods, this would undoubtedly 
lead us back through Herbart, with his attempt to 
found a mechanical and mathematical psychology, to 



new work. 



1 6 Experimental Psychology 

Leibnitz's Leibnitz to whom no human interest ever seems to 
nnwwnr? 6 have been foreign, ranging as his mind did through 
metaphysics, mathematics, law, and theology, as well 
as through the minutiae of practical concerns, whether 
of diplomacy or of calculating machines or of the 
shaping of optical lenses. May the experimental 
work in psychology always be worthy of its great 
progenitors ! 



CHAPTER II 

THE GENERAL CHARACTER OF PSYCHOLOGICAL 
EXPERIMENTS 

The more striking influences that established the The relation 
experimental method in psychology have been indi- J^^aHo" 
cated in barest outline. The present chapter will physiological 
be occupied in showing some of the important char- ex P erlments - 
acteristics of psychological experiments, and first of 
all their relation to physiological investigations. 

Why was it that the experimental mode of inves- why were 
tigating the mind came, in the first instance, chiefly P h y slol °g lsts 
from among the physiologists rather than from those here? 
upon whom psychology had a more immediate claim ? 
The explanation itself is, I believe, a psychological 
one. The physiologists would perhaps say, as indeed 
many of them have said, that it is because they them- 
selves have the only true method of getting at the 
mental life scientifically ; that the only sure avenue to 
the mind is through the nervous system, and that the 
professional psychologists who until recently have 
always tried to get at the facts in some other way 
were of course doomed to failure. One can experi- a proposed 
ment y some have said, only on the nervous system, and exp anatlon 
the older introspective method to which the psy- 
chologists clung, naturally excluded the experimental 
procedure. For this reason experimentation had to 
begin outside the ranks of the psychologists, 
c 17 



1 8 Experimental Psychology 

which is This, however, is certainly not the true explanation. 

wrong. p Qr ^ as a matter f f actj there exists no inherent in- 

compatibility between introspection and experiment. 
Was not Goethe's study of the effect of color upon the 
feelings experimental, even though the experiments 
were indeed very simple ; and was it not also intro- 
spective ? He used his variously colored glasses, and 
directly observed the inner moods that they occa- 
sioned. He did not get at the character of this mood 
indirectly by first noticing what effect the glasses 
exerted upon his nervous system. One may success- 
fully perform such an experiment and a host of 
others infinitely more complicated, and be as innocent 
as a babe of nervous physiology ; he might believe 
that he thought with his spleen or " reins," and yet 
be competent to tell that blue was sobering, while 
yellow and red roused like a bugle. This does not 
mean that one could at the present day master 
psychology as a whole and yet ignore physiology, 
for physiology has made some of the most important 
contributions of the time to the subject. But so far 
as the merely abstract possibilities of the case are 
concerned, experimentation might have grown up in 
entire independence of the physiologists — might have 
developed among those given to introspection pure 
and simple. 

The fact remains, however, that the experimental 
method actually did not so develop, but came from 
the physiologists chiefly, and the psychologists finally 
adopted it because they found others getting psycho- 
logical results by its means. 

The explanation is to be found in the law of mental 



Character of Psychological Experiments 19 

habit. Psychology had for centuries been intimately influence of 
connected with metaphysics, the same group of per- ^"habit 
sons cultivating both fields. It was the most natural 
thing in the world, therefore, that the methods which 
alone are applicable to pure philosophy should also 
be employed in the subordinate work. If one could 
study metaphysics with acids and microscopes, psy- 
chology would have had its laboratories centuries 
ago. The physiologists, on the other hand, were 
already familiar with experimentation, led to it com- 
paratively early because their problems more readily 
suggest the possibility of experimental attack, and 
also because the practical exigencies of sickness and 
of health make physiological questions more insistent 
than those of psychology. We must get exact knowl- 
edge of our bodies or suffer for it, while we can be 
in Egyptian darkness as regards our minds, and yet 
have contentment and long years. The close con- 
nection which exists between physiology and chemis- 
try, one of the earliest centres of experimental work, 
doubtless also contributed to the same result. So 
that when a physiologist in order to solve his own 
problems had to approach them from the psycho- 
logical side, as he often must, he naturally went to 
work by the methods to which he was accustomed 
and whose value had been so often forced home. 
The pure psychologists, on the other hand, were not 
accustomed to such ways, and therefore had to see 
the thing done before they could recognize its value. 

It must be confessed, however, that the experi- 
mental side of psychology, whether it be in charge 



20 



Experimental Psychology 



Suspicious 
look of 
psycholog- 
ical exper- 
iments. 



Are they 
not physio- 
logical exper- 
iments 
in disguise ? 



The way to 
allay this 
doubt. 



of those who call themselves psychologists or not, 
does to many persons look like a matter of physiology, 
pure and simple. For this reason it is not uncommon 
to hear this whole side of the subject spoken of as 
"physiological psychology," as if it had to do very 
largely with brain-processes and nerves. Many 
of those who take this view doubtless feel in their 
heart of hearts that experiments of this kind must of 
necessity belong to physiology ; that it is strictly 
impossible to experiment on the mind itself, it is 
so coated over with nerves and skull and skin, and 
that we can at best obtain by such experiments only 
some facts about the sense-organs or our nervous 
structure generally. This would seem to explain 
also the early precedence of the physiologists in 
the experimental work, as well as the fact that so 
many of our best modern psychologists began life 
as physiologists — Lotze, for example, and Wundt 
and James. 

Perhaps the best way to disabuse our minds of any 
lurking suspicion that psychological experiments are 
only physiological experiments in disguise, is to select 
some simple instance and analyze in careful detail its 
character and meaning. Much depends upon the 
selection, one must acknowledge ; for some of our 
"psychological" experiments are undoubtedly noth- 
ing but physiological, and no time should be lost in 
trying to claim them for the mental side. There are 
others, however, which are psychological — are experi- 
ments on the mind itself, as distinct from its nervous 
basis. A single example of the right kind will be 
logically sufficient for our purpose. 






-^ 



FIG. i. — Apparatus for determining the most rapid succession of 
light sensations. 




FIG. 3. — Reaction experiment. Part of the apparatus in the 
conductor's room. 



Character of Psychological Experiments 21 

Let us take a very humble experiment, then, — one Examination 
that is as near the line between psychology and physi- ^vomWe ex- 
ology as can well be imagined. If the problem may ample: the 

•1 , • , r flicker exper- 

be put in a very concrete form, suppose we were con- iment 
structing a kinetoscope and wished to know how many 
pictures a second would have to be reeled off to give 
the effect of absolute and unflickering continuity in 
the moving figures ; or, to express it in a more general 
way, with what frequency must successive flashes of 
light come to the eye if they are to fuse into one 
uninterrupted impression. We arrange some simple 
contrivance — we look through a revolving disc with 
slits in it, behind which is a light, as in Fig. 1 — and 
gradually increase the rate at which the flashes come, 
until a point is finally reached where the distinct and 
separate impressions merge into one long unbroken 
light. This limit is found to lie somewhere in the 
neighborhood of forty flashes a second, but varies 
considerably according to the conditions of the ex- 
periment. 1 

Now this is an old experiment among the physiolo- it appears to 
gists, and most persons would, perhaps, be inclined b h p s "o dy 
to say that it is purely a physiological matter. It is logical; 
simply a case of after-image or reverberation in the 
eye. When the flashes come so close upon each 
other's heels that the nervous excitation caused by 
one flash has not entirely passed away before the next 
one is upon it, there is a continuous stimulation of the 
retina, and the flashes fuse into one. The experiment 
merely determines the rapidity of the retinal process 

1 With a very bright light the limit runs as high as fifty flashes a 
second; with a very dim light, as low as twenty. 



22 Experimental Psychology 

in the eye (such persons might say) and tells us 
nothing about the mind at all, except, perhaps, that 
the mind is subject to the eye's action and cannot 
experience the flashes as separate when the nervous 
excitations no longer keep apart. 

If, in order to class an experiment as psychological, 
one had to make out an exclusive claim for it, such a 
showing as this would, of course, require us to sur- 
render the experiment to the physiologists. But the 
fact is, the experiment belongs to both parties, and 
however much the physiologists may obtain from it, 
yet it begins this does not diminish in the least what is there for 
TOwhoiogi- psychology. The experiment certainly does reveal 
cai features, the behavior of the nervous coating of the eye ; but 
how does it reveal this ? Only indirectly, by first dis- 
closing a peculiar psychological fact. In performing 
this experiment we cannot see the retina itself so 
as to say from direct observation that the nervous 
excitations outlast the flashes and finally fuse into 
one. What we do actually observe is that the sensation 
seems to become continuous, although from the condi- 
tions of the experiment we know that the light itself 
is being successively interrupted. The experience 
here does not correspond to the outer facts, and from 
this incongruity we infer the persistence of the retinal 
process during the interruptions of the light. The 
curious psychic effect, then, is the first thing observed, 
and the physiological part of the result is an after- 
thought, we might say, to account for this immediate 
psychological result. Strictly speaking, the physiolo- 
gist is here getting at the nervous process by an 
indirect and psychological procedure. He cannot 



Character of Psychological Experiments 23 

observe the nervous action itself ; so, from an ob- 
server's report as to where the mental effect ceases 
to correspond exactly to the outer facts, he learns 
indirectly at what point the nervous shocks overlap 
and how long each persists after the outer light itself 
has died away. 

So that along with the physiological bearing of this and sheds 
experiment, it makes evident an interesting fact of ^^ 
our mental life. It shows us that our visual impres- mentaifacts, 
sions have an upper limit of, say, fifty separate sen- 
sations a second, and that we cannot, by any known 
contrivance, make them run with higher frequency. 
And this becomes the more interesting psychologically 
when it is seen to offer an explanation of certain other 
mental facts. Taken in connection with a similar 
experiment on our sense of hearing, we can explain 
why a lapse of time marked off by two flashes seems 
shorter than the same interval marked off by two 
clicks ; this, in turn, may explain some further fact, 
and so the science of mental phenomena be furthered 
by experiments that seem at first to teach us only of 
our bodies and to have no connection whatever with 
the mind. 

In still another way this experiment might be shown The flicker 
to be justly of interest to psychologists. I am, of ^hl™™* 
course, using this particular experiment merely as a dissected, 
type and as a means of making clearer the nature of 
psychological experiments in general. It is a fair 
example, I think, to assist us in distinguishing the 
psychology of our experiments from the physiology 
which mingles so freely with them. If we can bring 
out the difference here, even at the risk of mak- 



24 Experimental Psychology 

ing some overdraft on the reader's attention, it will 
a fortiori be plain sailing in the more obviously 
psychological region of memory and pleasure and 
suggestion, which will be reached in later chapters, 
its results are From what was said a moment ago, it might seem 
explained by t ^ iat ^ e f acts that appear in the flicker experiment 
the charac- (as we may conveniently call the one with the flashes 
inai°process, °^ %ht) could be fully explained by the physical 
process in the retina. The results, however, cannot 
be entirely understood in this way, and on closer 
examination become of even more interest to the 
student of mind. The experiment shows that when a 
frequency of about forty flashes a second is reached 
the flicker usually disappears. It might seem that this 
limit of forty flashes a second was determined by the 
character of the nervous process in the eye, and that, 
as soon as the successive excitations began to over- 
lap, the flicker ceased. But if this were true, — if the 
overlapping of the successive processes in the retina 
were the complete explanation of the apparent con- 
tinuity of the light, — then, instead of having to run 
our flashes up to a frequency of forty a second, four 
or five flashes a second ought to suffice. For the after- 
image of each flash certainly lasts a fifth of a sec- 
ond, and usually much longer. A boy with a glowing 
brand does not need to whirl it round the circle in less 
than this time to make what seems a complete ring of 
fire ; the sensation lasts over the full interval and fills 
the gap. But why do we not lose the sense of revo- 
lution altogether and see only a steadily glowing rim ? 
It is not because the boy cannot keep to his circle 
and, therefore, never returns exactly to the point of 






Character of Psychological Experiments 25 

beginning ; for fasten the coal to a revolving wheel 

where the circle is perfect, and the motion is still seen, but are due 

But even when the circle is glowing full round, the lar s el y to 

^ ° our power of 

point where the ember actually is appears perceptibly discrimina- 
brighter than the other portions of the circle, and we 
see this brightest point pass round and round, and so 
feel the movement, although the entire ring is all the 
while aglow. We are able to distinguish the brighter 
portion from the dimmer, and see it move. But sup- 
pose the boy could whirl the brand so evenly and so 
swiftly that the coal rounded the circle before the 
after-image had time to fade perceptibly dimmer than 
the coal itself — then the whirling would appear to 
cease, and we should see one steady, moveless ring. 
So with our flashes. It is not enough that they should 
come so close together that the second is there before 
the first has entirely died away ; they must follow so 
swiftly, the one upon the other, that the second flash 
is there before the first has faded enough to be per- 
ceptibly different from the oncoming flash. It is not 
necessary that it should not have faded at all ; some 
slight fading it is probably impossible to avoid, so long 
as there is even the smallest interval of time between 
the flashes. The fading must simply be too slight for 
us to notice it. 

This, then, is the additional factor which helps to 
make this physiological experiment also a psychologi- 
cal one. The results we get depend not entirely upon 
the eye but also upon our power of detecting fluctua- 
tions in our experience. If our powers of comparison and to 
were less fine, then larger fluctuations of light would jj^ t s lticular 
go unnoticed and the flicker would seem to die away 



26 



Experimental Psychology 



Summary of 
the psycho- 
logical mean- 
ing of the 
experiment. 



Distinction 
between 
psychologi- 
cal and 
physiological 
experiments. 



with far less than forty flashes a second ; if it were 
nicer than it is, the flashes would still appear to come 
in succession, even though we increased our rate to 
80 or 100 or 1000 a second. A humble experiment 
like this, then, which at first seems so alien to the 
psychological realm directly teaches us far more of 
the behavior of the mind than of the nerves. It 
shows us not simply that there is a rapidity of expe- 
rience beyond which we cannot go, but that this 
depends upon our power of comparison, and that 
here, too, there is a limit. There are differences in 
our sensations that escape us, not because they are 
too minute for our outer sense, but because they are 
too fine even for our "inner sense." We get indirect 
evidence that they are in the mind, but we can never 
directly notice them. 

Where you class an experiment depends, therefore, 
upon what you are seeking. For a person of physio- 
logical interest, this and many of our other experi- 
ments are purely physiological; he heeds only the 
nervous data which they afford, and the mental side 
is a mere lever by which to pry out the hidden bodily 
facts. Another person using the same apparatus and 
performing the same acts is watching all the while 
the working of the mind, and for him the investiga- 
tions are psychological. For this reason psychologi- 
cal experiments, in their purpose and results, although 
not always in their apparatus and procedure, are dif- 
ferent from physiological research. In making such 
a distinction, however, there need be no thought of 
relative value or superiority. It is not that psychol- 
ogy would be defiled if found consorting with the 



Character of Psychological Experiments 27 

flesh; but only that there would be no logical justifi- 
cation for speaking of psychological experiments and 
psychological laboratories, if in reality all such work 
contributed only to our knowledge of the nervous 
system and told us nothing whatever of the mind. 

But those who admit that there really is a psycho- But is not 
logical side to these experiments are often quite con- the r or ? 4 

° jt 1 confined to 

vinced that the field of the work is extremely limited, the beggarly 
and has to do only with the beggarly elements of ^^ ts ° 
mind. This conviction arises from the fact that the 
experiments always involve the use of the senses. 
Whatever the mental process we are experimenting 
upon, — whether it be our sense-perception or mem- 
ory or discrimination or our feeling of pleasure, — 
the apparatus is always contrived to play upon our 
sense-organs. Colors are presented to the eye, tones 
come to the ear, strips of paper or of wood are offered 
to the touch. Fastidious spirits, on noticing this 
characteristic of the experiments, have often been 
offended by them ; the work seems to cling to the 
earth and to miss the higher flights of our mental 
life. If the experimental work be not physiological 
outright, they hold, it can at least never get above 
the basement levels of the mind. Since the appara- 
tus always operates upon the senses, this new method, 
it is urged, applies only to sensational processes, to 
tasting, smelling, hearing, seeing; while the higher 
operations in which we are chiefly interested, — con- 
ception, imitation, thinking, preference, — all these 
must necessarily lie beyond its reach. 

The subsequent chapters will, I hope, be the main 



28 Experimental Psychology 

An iiiustra- disproof of this. But to illustrate how mistaken the 
tion m reply. v j ew j Sj an( j now easily an experiment may pass beyond 
the bare process of perception, even though the appa- 
ratus primarily gives only impressions of sense, let us 
take an experiment on our power to recall the tem- 
poral order in which a series of experiences occurred. 
Experiments Some simple contrivance is used for showing at the 
with colors same opening of a box a series of, say, eight colors at 
slow and regular intervals, and thereafter, on com- 
pleting the series, any one of the colors, haphazard, is 
shown a second time, and the person experimented 
upon is asked to tell at what place in the original series 
this special color appeared. Now if the colors of the 
entire series be of the familiar sort that are easily 
recognized and for which we have ready names, — 
like red, green, orange, — the number of errors which 
will be made in recalling the place of the single color 
in the series is much smaller than when the colors are 
of rare and less readily namable hues, like drab, 
buff, and olive, 
or forms And to show that the results here are not due 

to the particular colors, we may use instead various 
black and white figures. For the more familiar 
group let us take our ordinary English letters, — K, 
S, B, M, F, P, H, C, for example, — and as a con- 
trasting series, difficult to name and classify, we may 
employ such nonsense characters as are shown in 
Fig. 2, which are certainly as striking and as dis- 
tinct inter se as are our familiar consonants. The 
results, however, are the same as before ; the order 
of the unfamiliar forms is much harder to remember 
than that of the letters. In these experiments the 



Character of Psychological Experiments 29 

apparatus seems to appeal only to the senses; it 
offers bare impressions to the eye. And yet, in spite 
of this, the actual result is to bring out an interesting 
peculiarity of the mental process of recalling and 

A of d-T J ~ 9 

FIG. 2. — Forms for experimenting on memory. 

"placing" an item in a time-series. It tells us noth- 
ing of our sensuous nature. For no one can suppose may give 
that the less familiar colors and shapes make a less ^ e ^ e ° f 
living impression upon the eye, and for this reason mental traits. 
are more difficult to remember. The larger number 
of errors here is rather due to the intellectual confu- 
sion we feel while the series is being given ; we hesi- 
tate over their names and character, and in the end 
have but a vague recollection of the order in which 
the series ran. The retention of the arrangement of 
such things is, to put it otherwise, largely a matter of 
recognition and verbal association ; especially when, 
as in the present instance, all logical or causal con- 
nection of the various members of the series is rig- 
idly excluded. 

To the careless onlooker we might seem here to be why the ex- 
experimenting on one's eyes, but in reality it is an P enments 
experiment upon the influence of recognition and doggedly 
verbal associations on our retention of a series in sensuous - 
time, and the results reached are doubtless applicable 
to any series whatever, whether of sights or of odors 
or of the most abstruse conceptions in mathematics or 
theology. The colors and letters are mere corpora 
vilia ; we can readily get them into the laboratory ; 






30 Experimental Psychology 

they are more manageable than a series of mathe- 
matical conceptions would be for most of us. But 
the result is just as far-reaching, goes as deep into 
the core of things, as if we were experimenting with 
naked abstractions like the idea of space of n dimen- 
sions, or that of the four classic virtues. It is as in 
an investigation in physics : an ill-smelling oil lamp 
is often better than a star. By confining our psy- 
chological experiments to conditions that are as 
simple and tractable as possible, there is doubtless a 
loss of picturesqueness, and to the casual visitor the 
work is apt to seem unspeakably trivial. There is a 
narrow round of clicks and revolving disks and of 
peering through slits in paper screens, until it seems 
as if the experimenters must lack imagination, cling- 
ing as they do to such insipid stuff. But at least, 
in this case, the end justifies the means, and the 
practical gains from this apparently wooden and 
passionless procedure more than offset the loss on 
the aesthetic side. 
Range of It is therefore a mistake to suppose that the experi- 

psychoiogi- men tal method has to do only with the rudiments of 

cal expen- J 

ments. psychology. Even if the method were so confined, 

there would be no need of apology ; but we should 
perhaps have to say that the glow of enthusiasm with 
which many have entered upon the work was prema- 
ture. I would not seem to magnify the more recent 
tendencies. One may well appreciate that psychology 
was by no means a failure before it reached the ex- 
perimental stage, and that some of our most interest- 
ing mental processes are exceedingly difficult to deal 
with in the laboratory. But admitting all this, it is 



Character of Psychological Experiments 31 

nevertheless erroneous to hold, as many do, that there 
is some fundamental and inherent limitation in the 
method itself. So far as one can now see, the method 
is equal to almost anything ; the rest is a mere ques- 
tion of genius in the psychologists themselves. What 
is needed is wit to adapt the method to the problems 
in hand. But already at the very beginning of the 
work there is hardly any great class of mental phe- 
nomena that has not been experimentally approached 
in some way. The range of these studies has so 
rapidly enlarged that the enumeration of the varied 
contributions would be as long and monotonous as 
Homer's catalogue of the ships. The subsequent 
chapters will aim to give an impression of their scope 
and purport in some of the more important directions. 

And now a closing word as to the place of experi- Their place 
ments among the general resources of psychology. mthe science 
Although the experimental trend came in historically 
from the physiological side and with some show of 
hostility toward the older introspective method, we 
have seen that there is no essential antagonism be- 
tween the experimental method and introspection. 
Introspection is really at the bottom of every method 
in psychology, and without the initial data which 
self-observation affords none of the so-called " objec- 
tive " methods in psychology could make so much as 
a start. So that we must not become partisans and 
cry up the new as if it could utterly supplant the old. 
For this reason it seems ill-advised to attempt an 
absolute separation of experimental psychology from 
psychology based upon other methods, as if the ex- 
perimental studies should make up a science of their 



32 Experimental Psychology 

own — something apart, ami not to be contaminated 
with the results oi more observation. In discussing 
tin* various questions upon which experimentation 

easts an important light, there will consequently be 

no attempt to look at these problems exclusively in 
this light, it the experimental side is emphasized, 

it is not in a party spirit ; there is no question oi 
principle involved, and there is the freest admission 
of the value of other modes of attack. 



CHAPTER III 

THE POSSIBILITY OF MENTAL MEASUREMENTS 

The subject of this chapter plunges one into the The problem 
heart of the experimental work. To many the sue- ^ f e ™ e J ure " 
cess or failure of the new departure in psychology momentous 
seems to hinge on the question whether mental facts [°^2 cho " 
will permit of being measured. If these can be meas- method. 
ured, they would say, then and only then is it possi- 
ble to have a scientific study of the mind. It is not 
enough that we should be able to perform experi- 
ments ; our experiments must be capable of giving 
us results that are quantitative. In the old school 
they were satisfied with determining the qualities and 
kinds of mental facts, but now we must discover their 
nicer mathematical relations. Psychology must have 
something comparable to the exact weights and vol- 
umes and durations with which the physical sciences 
deal and to which they owe their great success. It 
is held that unless we can make measurements in the 
mental realm similar to the quantitative researches in 
chemistry and physics, we are no better than our 
fathers, and the modern turn in psychology brings in 
no essentially new resources by which to lay bare the 
structure of the mind. The question of quantitative 
results in psychologv is therefore a living one ; it 
touches the subject in the quick. And while some 



34 



Experimental Psychology- 



Psychic 

measure- 
ment is 
declared im- 
possible. 



Common- 
sense diffi- 
culties. 



of us may think that those who regard this issue as 
a matter of scientific life and death are taking it per- 
haps too seriously ; yet, short of life and death, it is as 
important a problem of method as the experimenters 
have to confront. Experiments can certainly proceed 
even if exact measurements should prove impossible, 
but it would be a halting progress and a great dis- 
appointment to those who have heralded the new 
methods as the beginning of nicer and more fruitful 
work in this difficult field. 

The question is one upon which there are honest 
differences of opinion. No less a person than Kant, 
for instance, believed that mental measurements were 
an a priori impossibility. Those of opposite view 
may speak patronizingly of him as of one who lived 
under the old dispensation before our psychological 
laboratories had shown what was the range of pos- 
sibilities in the case. But we cannot so readily ex- 
plain similar views which persist to-day even amongst 
those who are familiar with all the details of the 
experimental work. Some who are entirely at home 
in the laboratory methods are still in perfect agree- 
ment with the Kantian doctrine, and when it comes 
to the question whether there are any strictly mental 
measurements in our modern researches, they answer 
with an unequivocal No. 

Our common-sense prejudice, I think, is apt to 
make us sympathize with this negative side of the 
matter. Probably most of us have an instinctive 
conviction that we can measure only the things of 
the physical world ; we can measure land or indi- 
cate degrees of temperature, and we understand what 



Possibility of Mental Measurements 35 

is meant by the weight of the human brain. But 
what should we mean by the literal metes and bounds 
of a man's mental life, or by a quantitative estimate 
of one's spiritual acts ? The use of mathematical lan- 
guage in regard to such things has a humorous effect, 
as when Plato tells us in the " Republic " that the just 
ruler is found by elaborate computation to be exactly 
729 times happier than the tyrant. The facts them- 
selves seem too vague and elusive for such treatment. 
Moreover, measurement seems to imply the applica- 
tion of the measuring apparatus to the object. But 
where, as in the present case, the facts to be meas- 
ured and our instruments of precision lie in totally 
different realms, what result can we ever hope to 
attain ? In some such way we might express the 
doubt that arises at the bare mention of the proposal. 

There is, however, a metaphysical objection that Metaphys- 
attacks the possibility of measurement in a much |j^ objec ~ 
subtler and more radical way. The common-sense 
objection is of a practical nature — the practical diffi- 
culty of bringing our measuring rod and our psycho- 
logical object into the same sphere and of applying 
the one to the other. But the more philosophical 
objection is, that even if we could carry our instru- 
ments into the mental realm, we should find nothing 
there that could possibly be measured. The very 
nature of mental facts is such that they are not sub- 
ject to measurement. The difficulty now is a logical 
rather than a practical one ; it is asserted that there 
is an inherent absurdity in the very thought of meas- 
uring mental things ; that between the notion of mind 
and the notion of measurement there is, to use Berke- 



36 



Experimental Psychology 



Need of 
examining 
instances of 
measure- 
ment. 



ley's phrase, a manifest repugnancy : the one concep- 
tion cannot tolerate the other. Measurement always 
implies that the thing to be measured is quantitative 
and may be stated in numerical terms and manipu- 
lated mathematically. The facts of mind, however, 
it is maintained, exclude any such idea ; they are not 
quantitative and are therefore not measurable. Math- 
ematics is inapplicable to the mental life, and for this 
reason psychology can never hope to attain the status 
of a science. 

This, in brief, is the a priori objection to all meas- 
urement in the mental field. It springs perhaps 
ultimately from a definition of the soul, as given in 
metaphysics. The soul is a simple substance, the 
metaphysics of mind has often taught — a simple sub- 
stance without parts and without extension. Such a 
description readily suggests that the soul has no 
quantum, and that measurement in its case is mean- 
ingless and impossible. 

The most telling refutation of such an argument is 
to do the thing that is alleged to be impossible — to 
prove that you can walk by walking. And this is 
the answer on which the experimenters, in the main, 
have relied. They are inclined to show their method 
and its results and to invite one to draw his own con- 
clusions. And we may follow them to the extent, at 
least, of postponing the consideration of the various 
theoretical difficulties until we have the character of 
the experimental work more clearly before us. We 
had better take up in some detail a number of charac- 
teristic experiments of the less complicated sort, and 
then, by a careful analysis, try to decide whether 



as to their 



Possibility of Mental Measurements 37 

they actually escape the grave objections that can be 
raised against the quantitative work. 

It is perhaps unnecessary to warn the reader that a warning 
experiments in this field are less ambitious than some 
may have been led to expect. There is no thought 
of measuring one's mind as a whole, nor of determin- 
ing its general range and efficiency. The expression 
" mental measurement " might suggest such a thought 
to the unwary. But if for this reason it seems objec- 
tionable, it is at least an improvement on an older term 
which at one time bade fair to be the designation for 
all this kind of psychological work — the term " psy- 
chometry." This word has fallen into disuse because 
it almost justified the belief that the laboratories pre- 
tended to some sort of mental caliper by which to 
determine the gauge of any given mind. An addi- 
tional reason for discarding it was that the theoso- 
phists adopted it to denote perhaps no one could say 
what, except that it was something totally different 
from what the psychologists ever intended. In men- 
tal measurements, therefore, there is no pretence of 
taking the mind's measure as a whole, nor is there 
usually any immediate intention of testing even some 
special faculty or capacity of the individual. What 
is aimed at is the measurement of some limited event 
in consciousness, such as a particular perception or 
feeling. The experiments are addressed, of course, 
not to the weight or size of such phenomena, but usu- 
ally to their duration and intensity. 

We might first consider, then, some experiments 
which aim to measure the time of psychic phenomena. 



38 



Experimental Psychology 



I. Examples 
of time- 
measure- 
ment. 



Apparatus 
and method. 



Without any apparatus at all we should be able to 
say that the duration of our mental processes varied 
enormously ; that to-day we can go through a mental 
operation in a few moments that once would have 
required hours. And if we were to attempt to meas- 
ure accurately by instruments the time required for 
some of our acts, we should have to use nothing short 
of an eight-day clock. The actual laboratory work in 
time-measurement, however, has been narrowed down 
to determining, not the time in general that is occu- 
pied by some mental action, but rather the shortest 
possible time in which a particular operation, like dis- 
crimination or choice or association or recognition, 
can be performed under the simplest and most favor- 
able circumstances. The experimental results here 
are something like speed- or racing-records, made 
under the best conditions of track and training. A 
delicate chronograph or chronoscope is used, which 
marks the time in thousandths of a second. 

The method generally employed is that of a " re- 
action " experiment, already alluded to in speaking of 
the astronomical observatories and the psychological 
experiments on personal equation. Some suitable 
object is suddenly disclosed to the attentive observer, 
he goes through a prearranged mental operation, and 
immediately at its completion moves an electric key 
on which his finger has been resting. The chro- 
nometer records the time between the display of the 
object (at which time, approximately, the mental pro- 
cess began) and the subject's movement which signals 
the close of the mental act. The time recorded, after 
making certain necessary corrections to be considered 




FlG. 4. — Reaction experiment. The arrangement in the subject's room. 
In actual experiment the room would be darkened. 




Fig. 9. — Apparatus for crossing the threshold of sound. In actual use 
the telephone would be in a distant room. 



Possibility of Mental Measurements 39 

directly, is assumed to represent the duration of the 
mental operation with which the experiment was con- 
cerned. 

To take a definite and concrete case, suppose we Reaction to 
wish to ascertain the time required for a person to lg ** 
become conscious of a light suddenly flashed into his 
eyes and to give a muscular impulse to his hand as 
a sign that the light was seen. An experimenter with 
his electric chronometer and connections, as shown in 
Fig. 3, is able to give a flash of light in a distant room 
and to record exactly the time when the flash was 
given. The person experimented upon, sitting ready 
and expectant (Fig. 4), moves an electric key, and in- 
stantly this " reaction " is recorded on the chronometer 
in the experimenter's room. The time between flash 
and movement would in the present case perhaps 
amount to from 180 to 280 thousandths of a second, 
according to the person's method of reacting. 

Now from such a record as this, supposing it to have Results, 
been checked and corrected by many hundred similar 
experiments, what do we learn as to the time occupied 
by the mental process of receiving and responding 
to the flash ? First of all, we know that the mental 
operation has occupied by no means all of these 180 to Necessary 
280 thousandths of a second. A considerable part subtractions - 
of the time has been used in the purely mechanical 
process of transmitting the message to the brain and 
of conveying the message back from brain to hand. 
It takes some time for the light to start a nervous 
excitation in the eye ; it takes additional time for this 
excitation to pass along the optic nerve to the brain 
and up through the brain to its gray surface. Not 



40 Experimental Psychology 

until this region — the cerebral cortex — has been 
reached is there any consciousness of the light. So 
that if our time-record were confined to the purely 
psychic and cortical part of the operation, it should 
begin, not with the external flash of light, but with 
the arrival of the message in the central office, when 
it reaches the gray matter of the hemispheres. And 
likewise with the transmission of the reply. If we 
could exactly mark the time of the mental process, 
our record would close at the instant the message 
had become formulated in the subject's mind, and 
the corresponding operation had taken place in the 
cortex. But instead, our clock keeps on and includes 
the time while the answer is coming from the motor 
region of the brain, down through the deeper cere- 
bral centres and the spinal cord and along the motor 
nerve out to the muscles that finally cause the finger 
to respond. The chronometer thus records a con- 
siderable amount of dead time — of time not required 
to begin and end the mental and cortical part of the 
work at all ; and to get at the time of the mental 
operation, this dead time would of course have to be 
deducted. 1 

1 In this chapter the timing of mental processes is illustrated only 
by the reaction method. There is at least one other way, however, 
that avoids some of the theoretical difficulty which the reaction method 
undoubtedly has. The flicker experiment of the preceding chapter, 
for example, might serve as an instance of timing our mental acts by 
a non-reaction method. It shows that the least noticeable fluctua- 
tions in vision can occur with a frequency of 20 to 50 a second, and 
therefore that each separate process occupies between 50 and 20 thou- 
sandths of a second. The view proposed in the text that there is here 
a kind of rudimentary discrimination of the successive intensities is to 



Possibility of Mental Measurements 41 

Such measurement is of value not alone from its a foundation 
inherent interest, but as a starting-point for further fo ^ rther 
work, in approximating the time of more complicated 
processes. One may next investigate the time re- 
quired not merely to receive the mental impression 
of light in general, but to recognize the kind of light, Recognition 
whether, for instance, it be red or blue or something time " 
else. The general character of the experiment would 
be the same as before, except that instead of repeating 
at each trial the self -same kind of light, the subject 
now never knows beforehand what the color of the 
light will be. At first he will probably be flurried, 
and his reaction will not be exactly according to pro- 
gramme ; but in time his nervousness subsides and 
he settles down to regular responses in which we can 
be reasonably certain that his reaction is not made 
until after he has discerned the color of the light, 
whereas at the beginning he may have reacted at the 
bare coming of the flash regardless of its hue. The 
time between light and reaction will under these cir- 
cumstances lengthen perhaps to 310 thousandths of a 

some extent confirmed by the fact that these numbers (20-50°") are not 
far from those obtained for discrimination or recognition (the two are 
not very different) by the reaction method. Titchener, for instance, work- 
ing by the reaction method (Philosophische Studien, Vol. VIII, p. 138) 
found that the recognition of a color takes place in about 30°". Cattell 
calculates from his reaction experiments that the discrimination of white 
light, when the kind of light had not to be discriminated, required for 
Subject B, 30°"; for Subject C, 50c {Philosophische Studien, Vol. Ill, 
p. 455). In the flicker experiment the interval is obtained without 
the need of computing what I have called the " dead " time, so that 
this particular difficulty is avoided. But the method is not so widely 
applicable as the reaction method has been found to be, and is there- 
fore on the whole less attractive. 



time. 



42 Experimental Psychology- 

second, as against 280 with the same observer where 
no recognition of the colors had to be performed. It 
is fair to assume that the increase of the interval — 
the difference between 280 and 310 thousandths — 
is the time required for this additional act; for in 
other respects the experiment has remained un- 
changed. 2 
Association By a similar modification of the reaction experiment, 

the details of which it is not necessary to describe, it 
is found that for an association of distinct ideas to arise 
in the mind (for "ship" to remind us of "sea," for 
example, or for "north " to recall "south") the reac- 
tion-time lengthens to a period ranging from 1.009 to 
1. 1 54 seconds in certain observers. It is interesting 
to note that if the person upon whom we are experi- 
menting is instructed beforehand to confine his asso- 
ciations to certain definite directions, the process 
takes less time than when he is given perfect free- 
dom to let in associations riotously from any point of 
the compass. If, for instance, he be required to call 
up some association that stands to the idea given him, 
in the relation of part to whole and we then give him 
the word "bear," he will get a definite association 
such as "skin," or "paw," in a shorter time than if 
he had the option of calling up an association of any 
kind whatever, like "mammal," "fur," " North Pole," 
or " honey." The very number of things coming, in 
the latter case, seems to choke the avenues of the 

1 For concreteness' sake I have taken the numbers here from the 
experiments on Professor Titchener, as reported by himself. They are 
fairly typical. See his " Zur Chronometrie des Erkennungsactes," 
Pkilosophische Studien, Vol. VIII, p. 138. 



Possibility of Mental Measurements 43 

mind ; the crowding ideas produce an instant's dead- 
lock and confusion, whereas if nine-tenths of them 
were excluded at the outset, some one idea would 
rush through the gates the sooner. It seems to be 
an instance, on a small scale, of what appears in 
common life where men of limited view — " men of 
one idea" — are so often of great practical efficiency, 
while those of wider mental range can perform noth- 
ing of importance without first rejecting a host of 
suggested lines of action. If quickness were the one 
thing needful, rigid habit without options would be 
our best equipment ; for freedom of selection always 
means an initial hesitation and loss of time. 

As an example of experiments dealing with the 11. The 
intensity of a mental fact, we might select the phe- J^t 0?" 
nomenon of color contrast. It is well known that any psychic in- 
color tends to cast a complementary hue over sur- f!Tjn' color 
rounding objects that are not themselves highly contrast, 
colored. Shadows near bright colors take on these 
complementary tints in a striking way, since the 
shadow is subdued and more neutral in tone and 
therefore offers little color of its own to resist the 
contrast influence. For this reason shadows near 
green foliage or on the green sea or on brown or 
golden fields show a distinctly purple or violet hue, 
and in some of our modern works of art these con- 
trast purples have been brought out in such regal 
splendor that little else can be seen. 

Now contrast of this sort is a psychological effect 
(although doubtless mediated by physiological condi- 
tions), and, in a way, it can be measured. For experi- 
mental purposes it is more convenient to reproduce 



44 



Experimental Psychology 



the phenomenon on a small and unimposing scale 
with a revolving circular disk of paper arranged as is 
shown in Fig. 5, where there is an inner and an outer 
zone of some bright color, — say green, — and a mid- 
dle portion composed of alternate black and white 
segments. When the disk is rapidly revolved by an 
electric motor, these colorless segments fuse into a 
single uniform ring ; but instead of this middle band 
appearing a neutral gray (as a mixture of black and 





FIG. 5. — Disk for the produc- 
tion of color contrast. If 
the two cross-hatched zones 
be of bright green, the zone 
made up of black and white 
will upon rapid rotation take 
on (by contrast) a reddish 
hue. 



FIG. 6. — Disk for the meas- 
urement of the contrast 
effect in Fig. 5. The cross- 
hatched segment represents 
red, which may be varied in 
amount until the middle zone 
on rapid rotation matches 
the middle zone of Fig. 5. 



white should), it is seen to be decidedly tinged with 
red. If we cover the two green portions of the disk, 
the zone between them at once becomes colorless, 
showing that the reddish tint is a contrast effect due 
solely to the neighboring green. To measure the 
amount of this contrast hue, we set beside it another 
revolving disk which likewise has three concentric 
zones (Fig. 6) but whose inner and outer rings are 
colorless, while in the ring between them there is a 
variable sector of red which permits us to change at 
will the proportion of red and gray in this middle zone. 
By this second apparatus we can thus produce a series 



Possibility of Mental Measurements 45 

of grayish reds until we have approximately matched 
the reddish tone that appeared on our first disk by 
contrast. It is now found that from thirty to fifty 
degrees of the red sector must be exposed in the gray- 
ish ring of the measuring disk to produce an effect 
equal to the mere proximity of the green. Experi- 
ment shows that the number of degrees required for 
a match differs according to the person, the kind of 
green we use, the shade of gray, and various other 
conditions of the trial. It is in any case but an 
approximation, and I shall indicate later with what 
caution inferences should be drawn from these and 
similar results. 

A single additional example of measurement will in. Meas- 
suffice. We all know that the blind show an astonish- ureme " t of 

space cas- 
ing cleverness in using their sense of touch. Does crimination, 

their superiority to us lie in the fact, as some have 
thought, that their finger-tips have developed a much e.g. in the 
finer nervous structure than ours ? If so, experiment bhnd * 
ought to show that impressions so close together as 
to be quite indistinguishable for us were still separate 
enough for their finer sense. We should make care- 
ful experiments on the blind and on normal persons 
of like age and intelligence and of similar manual 
employments, to find what is the least space difference 
that each class can discriminate. 

By measuring the spatial nicety of their skin with 
compass-points, — that is, by finding how far apart 
the two compass points must be for the subject to feel 
them as two and not as one, — we learn that in chil- 
dren (whose sensibility in this respect is in general 
finer than that of adults), it is necessary to open our 



46 Experimental Psychology 

compasses a little more or less than one millimetre 
(about one twenty-fifth of an inch) before the two 
points seem to lie on distinctly different places on the 
skin, — a result practically the same as that which we 
get by similar experiments on children who can see. 1 
There is, perhaps, a slight advantage on the side of 
the blind, but nothing sufficient to account for their 
deftness in using their sense of touch, as in reading. 
The tactile superiority of the blind is not due, then, 
to some extraordinary development of the organ of 
touch. They do not obtain through their fingers in- 
conceivably finer gradations of impression than we do, 
but by long practice and attention they have learned 
to see a world of meaning in the very impressions 
which we receive as tame and unsuggestive, distracted 
as we are by the more interesting sensations of light 
and color. The blind have little if any greater nicety 
of the sense itself, but infinitely greater readiness in 
understanding the meaning of what the sense reports. 

1 This result, already indicated by earlier experiments (cf. the 
authorities in Heller, " Studien zur Blinden-Psychologie," Philosophische 
Studien, Vol. XI, p. 226), has been confirmed by the experiments of 
some of my students, courteously aided by Dr. Wilkinson, the super- 
intendent of the California State Institution for the Deaf and Blind. 
Miss Katharine Bunnell, working with five blind subjects and five 
normal persons, and Miss Agnes Stowell, with a separate group of 
subjects (eight blind and eight normal), find the thresholds to be but 
slightly in favor of the blind. 

As regards the least pressure that can be perceived at all — a ques- 
tion to which experimenters on the blind have given far less attention 
— there appears to be a decided advantage for the blind, according to 
some preliminary experiments by one of my students, Mr. Otto Schulze. 
As to the meaning of this, I should prefer to reserve judgment, how- 
ever, until the results are quite beyond doubt. 



Possibility of Mental Measurements 47 

It is as in the case of language, where the same 
sounds give such different results according as they 
are or are not of our mother tongue. In listening to a 
language, the native and the stranger are on an equal 
footing so far as the mere sense of hearing is con- 
cerned ; and yet, even when the stranger knows the 
tongue quite well, he must stand nearer a speaker 
in order to understand him. The native can disen- 
tangle the snarl of sounds, can catch the signifi- 
cance of slight differences which to the other are as 
good as lost. Our experiments in measurement give 
some hint, then, not only of the general character of 
quantitative work in psychology, but also of the use 
to which the results can be put in clearing up more 
complicated mental problems. 

With these instances of laboratory measurement Return to the 
we may return to the question raised at the beginnine; on s inal 

J *■ 00 question: Do 

of the chapter. Can such experiments justly claim such exper- 
to measure mental phenomena, or must we, in spite of lments reall y 

r ' > .. sr measure 

them, reaffirm that quantitative notions are absolutely mental pro- 
alien to the mental realm ? We are now in posses- cesses ? 
sion of the main facts of the case, and must next try 
to render some decision upon this question. Here And, first, 
the hard work fairly begins, I fear, and the reader ls s *^ any 
must prepare for a somewhat trying review of the quantity to 
various difficulties in this subtle but important prob- 
lem. After all, a closer examination of the theoreti- 
cal objections to the experiments in measurement is 
the best means of seeing what the experiments them- 
selves really are. 

The hottest of the dispute has been over the 



measure ? 



4 8 



Experimental Psychology 



Review of 
four kinds of 
quality 
available : 

i. Intensity. 



The claim 
that every 
mental phe- 
nomenon is 
one and 
indivisible. 



But so is a 
tree, strictly 
speaking. 



intensity of psychic processes, and more particularly 
over the intensity of sensations. For no one, so far 
as I know, has ever seriously claimed that there is 
any intensive character to the mental activity whereby 
things are held in relation and bound into wholes, — 
as, for example, the mental act of connecting two 
ideas logically, as subject and predicate in a judg- 
ment. So that intensity is to be found, if at all, in 
sensations and feelings — in the materia prima of 
consciousness, rather than in its "form." 

Fechner's famous elaboration of Weber's Law pro- 
ceeded on the assumption that the intensity of any 
sensation is a definite quantity made up of a certain 
number of units of intensity, and that sensations of 
different strength might in this way be mathemati- 
cally compared. This assumption, however, has been 
denied in toto. A sensation, it is claimed, is not made 
up of a number of units. Within the sensation which 
an arc-light gives, for instance, we cannot discern a 
number of weaker sensations, each like the light of 
a tallow candle. A loud sound, as an experience, 
is not composed of smaller faint sounds ; we cannot 
break it up into a weaker sound plus a certain in- 
crement ; it is an absolutely indivisible and unitary 
experience. 

This is certainly a forcible argument, and yet I am 
not sure that we should give it decisive weight. For 
might we not similarly point out the absurdity of at- 
tributing spatial quantity to trees, since a big tree is 
not a collection of little trees, nor can we break the 
large one up into a smaller tree plus a certain incre- 
ment ; the larger tree is not a compound, it is a single 



Possibility of Mental Measurements 49 

and unitary thing. And yet it is not the less a space- 
extent. So that even if we admit that each mental 
event is something entirely unique, this does not 
preclude its having some single aspect — like that of 
quantity — common to other mental events. Any- 
thing in the world, whether it be a tree or so simple 
a thing as a sensation, has many sides, and nobody 
should pretend that the quantitative aspect is more 
than a single one of these, hidden among many 
others, and recognizable only by a subtle process of 
abstraction whereby the numberless differences and 
contrasts between this and other objects are for the 
time neglected. One need not discover little trees in 
the large one, nor even yardsticks in it, in order to 
attribute to it linear quantity. We neglect the differ- 
ence in wood between the tree and the yardstick ; 
we neglect their difference in shape and color, as 
well as the fact that at bottom a tree is not a com- 
pound but is an organic unit, and cling to the sheer 
abstract extent which both objects display. Similarly Anindivisi- 
the loud sound undoubtedly does come to us as a ble ex P erl - 

J ence may be 

unitary thing and not as a compound. It arouses quantitative, 
feelings and impulses that are totally different from 
those of a faint sound, so that as an experience it 
has a peculiar quality and flavor which the other 
lacks. And yet this does not argue that the two 
lack the single common feature of strength as a 
strictly quantitative matter. Whether it is possible 
to measure and mathematically express their relative 
strength — that is another question, to be discussed 
later. Here we are concerned solely with the high- 
handed objection that there is no quantity in mental 



50 Experimental Psychology 

things to measure, and that we may consequently with- 
out more ado declare all attempts to measure them 
futile and absurd. And so far as the present argu- 
ment goes, we may bring in a verdict of not proven. 
Yet even if It ought perhaps to be added, that this particular 

should feii question in regard to the intensity of mental processes 
ail is not lost, does not seem to me so vital for even our laboratory 
measurements (not to speak of the large amount of 
work that does not pretend to measure anything) as 
many have supposed. The justification of the quan- 
titative work does not stand or fall according as we 
can allay all doubt of the existence of intensive 
quantity in sensations. For even should we concede 
the whole point, there still remain plenty of other 
kinds of quantity (such as temporal, spatial, and 
merely numerical quantity) to give scope for research 
in measurement. And as a matter of fact, the most 
systematic attempt that has yet been made to sweep 
away the notion of intensive quantity from psychol- 
ogy does not, in the end, really exclude all quantita- 
tive character from our sensations, but simply reduces 
intensity to quantity of another sort, to differences of 
time and space. According to this attempt at recon- 
struction, a loud sound seems to be more intense be- 
cause it occasions in us reflex muscular contractions 
of longer duration and of wider extent than does a 
faint sound. The involuntary muscular reaction per- 
sists through more time or is diffused through more 
space, and this purely temporal or spatial difference 
in the muscular accompaniment somehow casts its 
shadow over the auditory impression and gives to it 
the peculiar appearance which we call its intensive 



Possibility of Mental Measurements 51 

character. Passing over the obvious difficulty here 
that our muscular sensations seem also to have inten- 
sity in addition to their temporal and spatial character 
(so that we are as far as ever from ridding ourselves 
of intensity), the question sifts down to one of classi- 
fication, — whether intensity is a special and separate 
kind of quantity, or can be reduced to one of the 
other kinds ; and the experimenters can work as con- 
tentedly under one answer to this problem as under 
the other. It really makes little difference to them 
whether psychic quantities be thrown into one group 
more or one group less. That there should be quan- 
tity at all is the main thing ; not that there should be 
quantity of this or that particular name. 

As to the existence of spatial quantity in the psy- 2. Spatial 
chic realm, it has been usual for psychologists to q uantlt y m 
make no claim in that direction. Physical things, realm. 
it is held, have shape and size and position; but men- 
tal processes not. Our thought of a quart is not a Arguments 
larger thought than that of a pint. Our conception contra - 
of the north pole does not lie to the north of our 
conception of the south pole. The idea of half a 
circle is not a semicircular idea, etc. 

There certainly is no disputing these propositions. 
But they do not prove that space-relations have no 
place in psychology ; they merely show that space is 
not a universal form of our mental processes. For 
we could as well argue that mental facts have no 
time-character, since our idea of a century is not it- 
self a century long ; or that color is a purely physical 
phenomenon and not at all a psychological one, since 
our idea of green is not a green idea. 



5 2 



Experimental Psychology 



A distinction. The confusion clears up somewhat when we dis- 
tinguish between the object in mind and certain 
deeper mental processes that play around this object. 
Now space-character may justly be attributed to the 
object we have in mind, and yet be confessedly in- 
applicable to the higher mental activity that stands 
above and around the mental object or contents. In 
other words, some of our more elaborate processes do 
not have the same characteristics that the particular 
constituents of these processes possess. And conse- 
quently when we have shown the absurdity of assign- 
ing spatial quantity in the one case, we are far from 
driving this quantity quite out of the psychological 
field. 

Such an expulsion would be easier if there were 
not so many space-objects that have their existence 
only in consciousness, so that their spatial character 
cannot be coolly turned over to the physical world. 
The peculiar shapes and dimensions of many figures 
are sheer figments of the mind, as in our dreams or in 
the normal illusions of our waking state. The quan- 
titative aspect of these objects is clearly a mental af- 
fair, and any measurements we might perform would 
be a psychological measurement, pure and simple. 

illustrations. The interesting illusion that goes by the name of 
Zollner's figure might illustrate such a non-physical 
spatial quantity. In this illusion parallel lines cease 
to appear parallel as soon as they are cross-hatched, 
as in the accompanying diagram (Fig. 7). The ap- 
parent displacement of the parallels amounts, in my 
own case, to an angle of about four degrees. So that 
if the diagram be changed four degrees in the opposite 



Difficulty of 
denying 
space-attri- 
butes to the 
mind. 



Possibility of Mental Measurements $3 

direction to offset the illusory effect (as in Fig. 8), 
the lines appear to be parallel. The disturbance 
caused by the cross-hatching is a psychological fact, 
and is quantitative and spatial. It may, in the end, be 
due to some purely intensive effect of the cross-lines 
upon the muscles of the eye, although probably not ; 
but as we experience it the illusion is spatial, and as 




Fig. 7. — The lines AB and CD Fig. 8. — The lines AB and CD con- 

are really parallel. verge upward. The psychologi- 

cal effect of the cross-hatching is 
measured by the angle DCD', 
since CD' is parallel to AB. 
(ZDCD' = 4 °+). 

such we have to describe and measure it. Similarly the 
apparent enlargement of the sun and moon when near 
the horizon is, in all probability, a mental phenomenon, 
and is of course spatial. So that it would not seem 
amiss to make spatial quantity a valid category in psy- 
chology ; but valid only within limited regions, as has 
been said, and not of universal application. 1 

1 I have the less hesitation in presenting these conclusions in regard 
to the spatial character of mental phenomena, as well as in regard to 
their intensity, since finding that my view is in essential agreement with 



54 



Experimental Psychology 



3. Tempo- 
ral quantity. 



Reasonable- 
ness of 
assuming it. 



4. Quantity 
of simple 
enumeration 



It is less difficult to convince ourselves that tem- 
poral quantity has a place in the mental realm. It is 
true that for certain ends it is often necessary to 
regard the mind sub specie ceterni, and to neglect 
that side of it that shows duration and change. But 
whatever aspects of the mind there may be that are 
timeless, they are certainly not the ones with which 
empirical psychology has most to do. Psychology is 
largely concerned with acts of attention, with pleas- 
ure and pain, with the processes of perception and 
memory ; and can we justly maintain that these in 
their secret essence are timeless ? They have all 
the characteristics of events in time ; they come 
and go ; some are brief while others persist ; they 
come together ; they come in succession. A re- 
cent writer has denied that mental phenomena are 
temporal ; but it is difficult to see any better reason 
for this than there would be in the case of the 
phenomena of physics or of astronomy or of history. 
Psychology has as good ground for assuming the 
reality of time within its own field as have any of 
the sciences. 

And finally, if we are to complete our review of 
the quantitative aspects of the mind, we shall have to 
include still another, and that the most abstract of 
all. Professor Howison has clearly shown that 
wherever any real differences exist, there the funda- 
mental notion of quantity, that of number, finds a 



that of so able a writer as Mr. F. H. Bradley. See his two articles 
in Mind (N. S., Vol. IV, 1895) entitled respectively: "In what sense 
are Psychic States extended? " and " What do we mean by the Intensity 
of Psychic States?" 



Possibility of Mental Measurements $$ 

place. In this widest sense, quantity pervades the pervades 
mental world as truly as it does the physical. 1 For in realm!* 1 ** 1 
neither realm is there monotonous uniformity; on the 
contrary, there are distinctions and contrasts, and so 
the basis for number is at hand. As regards numeri- 
cal quantity, then, we do not have to make the reser- 
vations that were necessary in some of the other 
cases. There is no department of the mind that it 
does not penetrate. Hegel has shown that quantity is 
next-door neighbor to quality, and that as soon as 
anything possesses character it is ipso facto entering 
the quantitative field. The great theological debates, 
whether God is one or many; the problem of 
Monism and Pluralism, of Unitarianism and the 
Trinity — these are evidence of the exalted region 
into which men have felt that the notion of number 
goes. Whether there are real and abiding distinc- 
tions within the very Godhead, has seemed to many 
thinkers a relevant question. To escape it we should 
have to adopt something like the mystical view that 
spirit lies in a realm where none of our human predi- 
cates applies ; that it is neither one nor many, nor 
many in one, but is ineffably higher than all such 
marks. But certainly no psychologist can consist- 
ently accept this view as applying to the mind as 
we actually know it. For psychology is an effort to 
understand the mind, to map off and tabulate its 
different appearances and events. And those who 
carefully examine the subject believe that many 
differences and contrasts and variations in conscious- 

1 Howison, " Philosophy and Science," University Chronicle, Vol. V, 
p. 129. 



56 



Experimental Psychology 



ness are discernible. A process of reasoning is one 
thing, a sensation of pain is another ; each is one and 
the two are two. And in the flicker experiment, 
described in the preceding chapter, some thirty 
mental events occur in a second. The fact, however, 
that most of our mental phenomena dawn and 
change and almost insensibly fade away and, at 
best, have but the vaguest outlines is no better 
ground for denying them quantity than for refusing 
it to the clouds because they are often ill-defined and 
merge and vanish in thin air. 



But even 

though 
psychic 
quantity 
exist, is it 
measurable? 



Doubt be- 
cause of the 
inaccuracy 
of our experi- 
ments. 



There seems, then, an irresistible cumulative evi- 
dence that mental phenomena are quantitative. The 
remaining and more practical question is whether 
this quantitative character is really measured by our 
laboratory experiments. 

Perhaps the readiest doubt would be on the score 
of accuracy. The illustrations given earlier in this 
chapter indicate the difficulties and embarrassments 
under which psychology labors in this regard. Our 
results certainly make a poor showing in comparison 
with the marvellous exactness which marks the best 
physical measurements. In computing the amount 
of purplish red cast over the gray by contrast with 
the green, — one of the examples of psychological 
measurement given some pages before, — if we car- 
ried out the measurement in all its details we should 
be struck by the impossibility of making any very 
exact determination of the amount of red the green 
induced. In our attempt to match the red, we should 
find that, when once we had reached a certain point, 



Possibility of Mental Measurements 57 

a few degrees of red more or less in our meas- 
uring wheel would not disturb the match to any 
appreciable extent ; it would seem satisfactory re- 
gardless of the exact amount of the red sector dis- 
played, provided we kept within certain limits. In 
any single measurement, therefore, there is always 
the probability of a considerable error. And this 
holds true of all our other psychological measure- 
ments, — in the examples of experiments on the tactile 
sensibility of the blind and in the chronometric work 
which at first sight might seem to an untrained 
person a marvel of accurate investigation. Judged 
by the standards of astronomy or of physics, how- 
ever, such work is crude enough, and marks off the 
result as by a ploughshare where the others can use 
a graver's tool. 

But admitting all this, I feel that too much stress Even exact- 
can be laid on a matter so important, even, as that of ness can b * 

x overvalued. 

accuracy in measurement. Exactness is certainly a 

vital thing, and the psychological work must become 

vastly more refined. But accuracy is relative, after 

all ; and what we call the exact physical sciences ah measure- 

appear so only because we have no absolutely exact ™^ t s are m " 

measurements with which to compare theirs. Even 

in astronomy the measurements are, strictly speaking, 

but rough approximations. Yet the errors here offer 

no insuperable obstacle to reliable generalizations. 

Copernicus and Galileo in their most lasting work 

doubtless relied on observations which would be 

considered crude if judged by the standards of our 

modern observatories, and cruder still could we but 

look back upon them from the vantage of the coming 



5« 



Experimental Psychology 



Importance 
of knowing 
the range 
of error. 



Valid infer- 
ences from 
results that 
contain error. 



years. It is, therefore, no fatal objection to our psy- 
chological measurements that they are comparatively 
rough. Moreover, increased success is constantly 
being attained in excluding various sources of error 
and in measuring or estimating the amount of the 
errors themselves. When once we know how large 
the error in any given instance is, it often ceases to 
be a serious disturbance. As far as the special prob- 
lem in hand is concerned, we may proceed as if the 
results were accurate to a hair. If we found, for 
example, that when the contrast experiment was tried 
in the presence of music, one or two degrees more 
of red appeared in our results, we should hardly be 
justified in concluding that music tended to heighten 
the effect of color contrast. One or two degrees are 
too small in comparison with the probable error of 
measurement. But should our results regularly run 
up twenty or twenty-five degrees whenever the music 
was heard, we might justly feel some premonitory 
emotions of discovery. Or to take a case actually 
tried, we do find that when a sharp line is drawn 
between the green and the gray the results show such 
a falling off in the amount of apparent red that it is 
impossible to attribute it to an error of observation ; 
we are sure that it is a psychological effect produced 
in some way by the line. In spite of the roughness 
and error of the measurement here, we may unhesi- 
tatingly conclude that the effect of the green upon 
the gray is heightened by a certain lack of definition 
in the impressions themselves. Largely for this rea- 
son, contrast tints in the landscape are best seen 
through half-closed eyes. 



Possibility of Mental Measurements 59 

This seems to me to break the force of the ob- 
jection based on the inexactness of the laboratory 
experiments. No measurements, whether they be 
psychic or physical, are exact beyond a certain point, 
and the art of using them consists largely in checks 
and counter-checks, and in knowing how far the 
measurement is reliable and where the doubtful zone 
begins. And all this is quite possible in the case of 
psychological research. 

More acute and more difficult of answer is the Objection 
objection that the laboratory work, exact or inexact, ^lo^ST 
does not measure anything mental at all ; that what measure- 
is really measured in each case is some purely physi- ™^i s are 
cal fact — the excitation in our nerves or even some physical 
process in the world outside our bodies. Serious as 
this objection at first appears, it need hardly, however, 
disconcert us. 

For, in the first place, we must except from any certainly 
doubt of this kind the experiments on the duration of p^^ 
mental phenomena. If I look at my watch and see measure- 
how long it takes me to run through a chain of ten ment5, 
associations starting say with Transvaal, Transvaal 
reminding me of Krueger, this the Kriegerverein, the 
Franco-Prussian War, Paris, the Revolution, Carlyle, 
the burning of his Manuscript, John Stuart Mill, 
the Logic, — this process, I find, takes perhaps ten 
seconds. The ten seconds here are the duration of 
the mental process, as nearly as I can measure it ; 
and not primarily the time of some physical process, 
say that in the brain. The brain-process correspond- 
ing to this train of ten associations doubtless lasts 



6o 



Experimental Psychology 



The intensive 
measure- 
ments look 
suspiciously 
physical. 



about the same time ; but that is an inference once 
removed ; the direct observation is of the time of the 
ideas and not of the operation in the nerves. The 
nervous action is a relatively hypothetical affair, and 
to time it I have to work back from my immediate 
measurement of the mental facts. The measurement 
here, then, is first and foremost a measurement of 
mental occurrences. And the same holds true, al- 
though perhaps less obviously, of the delicate time- 
measurements in thousandths of a second, of which 
some examples were given earlier. Similarly the 
experiments dealing with the spatial and numerical 
character of our mental processes are primarily men- 
tal measurements. Whatever physical quantities we 
get in this way are secondary matters, inferred from 
the results of the mental observations. 

But when we pass to the experiments on the inten- 
sity of psychic phenomena, there does seem to be 
something strange and suspicious. In the first place, 
if we are really making mental measurements, why 
are not our scale and our units of measurement men- 
tal in character ? The standard or unit in every case 
seems to be a purely physical thing. In experiments 
on the sense of touch we may use a series of brass or 
cork weights, of grammes or milligrammes, — a physi- 
cal quantity, out and out, and not psychical in the least. 
And in the case of color contrast the units of inten- 
sity may be so many degrees of a physical sector of 
red paper of a certain texture and hue. But how can 
a mental phenomenon be measured by a physical 
scale ? As far as the strictly psychological processes 
are concerned, must not our results inevitably be as 



Possibility of Mental Measurements 61 

wide of the mark as if we tried to express the effect 
of the Choral Symphony in horse-power or in foot- 
pounds ? 

A doubt of this kind is natural, and yet it is largely The units of 
due to a misunderstanding of the real nature of the ™ent here 
standards of measurement here. Wh6n we say that are really 
the reddish contrast amounts, in one instance, to 20°, psyc IC ' 
and in another instance to 30 of red on our measur- 
ing wheel, we certainly do not mean that it is literally 
equivalent to a certain angle of a red paper sector. 
That would be absurd ; the contrast effect is not an 
arc or an angle at all. The more pronounced red in 
our revolving measure-disk is, as we directly experi- 
ence it, a purely intensive effect. For convenience' 
sake, we designate the different intensities by the 
angular measurement of the sector which produces 
them. But what we are really working with is a 
scale of intensive experiences. Our scale, or meas- 
ure, is psychic, although we speak of the different 
points on the scale in physical terms. 

And the same is true of experiments with weights, 
although not of all. We find, for example, that under 
one very definite set of conditions a person can just 
feel the difference between a weight of 100 grammes 
and one of 130 grammes ; but if we slightly alter the 
conditions the same person can distinguish between a 
weight of 100 grammes and one of 103 grammes. 
We use here the language of physical weights, but 
in reality we are dealing with the sensations which 
the weights produce. We find that by regular grada- 
tions of pressure upon the skin we can, within cer- 
tain limits, produce a graduated scale of sensations 



62 Experimental Psychology 

running from a barely perceptible touch up to a 
degree of violence where touch is swallowed up in 
pain. This series of sensations is the real psycho- 
logical scale, and the brass weights are the mere 
machinery for getting this before us. There is no 
ground here for the charge that our standards of 
measurement are physical and not mental. 

But are these But as regards the intensity of mental phenomena 
and S invafi- (^ e department which, all along, has given the most 
able? trouble), there is an additional difficulty which for the 

honor of the work one might feel tempted to pass by. 
There is certainly something here that is quite different 
from our ordinary conception of measurement. It is 
said, no doubt libellously, that in the early Mexican 
surveys in California the measure employed was a 
thong of rawhide which stretched with use, and that 
this accounts for the progressive increase in the length 
of the blocks, at Santa Barbara, for instance, as one 
walks back from the shore. Now it is barely possi- 
ble that there is something comparable to this in the 
psychological measurement of intensity. It is diffi- 
cult to prove that in these experiments the unit of 
measurement remains absolutely the same through- 
out the whole stretch to be measured. For, to return 
to the illustration of color contrast, the measurement 
was in terms of a scale of color intensities, or satura- 
tions, produced by a regular series of enlargements of 
a red sector, and the results were stated in degrees 
of this sector. On the physical scale each division 
of the arc of red paper is exactly like its fellows, 
— the tenth or the twentieth step is the same as the 



Possibility of Mental Measurements 63 

first. But we cannot be sure that this is the case in 
the series of mental intensities produced by the grad- 
ual enlargements of the sector. For aught we know 
each step in the mental scale may be different from 
its predecessors. All that can be confidently said is 
that the mental series is composed of a number of 
small additions, but we have no assurance that every 
addition which we call by the same name is really of 
the same amount. 

In fact, some have long felt that we have good ex- No assur- 
perimental reason to believe that any scale of inten- constancy 6 ^ 
sity in our laboratories, whether it be a series of reds 
such as has just been mentioned, or of pressure-sen- 
sations or of sound or temperature or pain, — that 
none of these scales is an ordinary arithmetical series 
where each member is as good as its neighbor, but 
that it is a gradually diminishing series in which each 
additional step carries us farther along, it is true, but 
not as much farther as did the one before. The thong 
here is supposed to shrink instead of stretch. There 
are others who believe, however (and they seem to me 
to have the better reason), that the different degrees 
or units of any given psychological scale are approxi- 
mately uniform throughout. But this is still debat- 
able ground, and the decision must be reached, if at 
all, by further patience and experimental sagacity. 
Until a solution is found our quantitative results in re- 
gard to intensity must give forth an uncertain sound. 
And yet, even before this defect shall have been made This does 
good, such measurements are by no means useless or not ™ ake the 

' J results value- 

without significance. In spite of their uncertainty less. 

they may serve as the basis for wide inductions. We 



of measure- 
ments. 



64 Experimental Psychology 

must simply avoid the obscure portion of our results 
and, as all scientists must do, base our inferences only 
on the portions that are sure. But it may not be 
out of place to repeat that the worst difficulties are 
confined to that single class of experiments which 
would measure the intensity of mental occurrences, 
and are not present in those dealing with the tem- 
poral or spatial or merely numerical quantity of the 
phenomena. 

The purpose And now a word as to the purpose of these meas- 
urements. Suppose that the measurements are valid, 
one might ask, of what use are they ? It has been 
claimed that there is a vast difference in the purpose 
of mental and of physical measurements ; that physi- 
cal measurements are for their own sake — are an end 
in themselves — whereas mental measurements are 
not. The truth is, that no sane person ever measures 
anything, whether it be physical or mental, just for 
the sake of measuring it. He measures in order to 
discover the interrelations of things. If the men- 
suration is not for some practical end, like that of 
fitting garments or of navigating the seas, it is for 
the higher utilities of intelligence — for the sake of 
understanding the relationships and laws in nature. 
We measure mental processes for a like purpose, to 
discover their connections and kinships. Psychology, 
like all the sciences, is earnestly concerned with lay- 
ing bare the causes and circumstances of the vari 
ous facts with which it deals, and since mensuration 
is of great assistance in attaining this result, one can 
well understand the interest a psychologist takes in 



Possibility of Mental Measurements 65 

the general inquiry we have had before us in this 
chapter. 

It is because the question of mental measurements Conclusion, 
is thus an important one for the laboratory work that 
so long a review has been made of the weightier ob- 
jections to the quantitative method. One might feel 
tempted to say that something must be wrong where 
so many objections can be raised. There is no need, 
however, of drawing this conclusion. After all, as 
Cattell has said in regard to these difficulties, 1 objec- 
tions can be raised to anything. In the present case 
the work is comparatively new, and seems to be more 
revolutionary than it really is ; and withal a good deal 
of partisan feeling has been aroused both within and 
without, with a resultant tendency either to magnify 
or to belittle the whole thing. Undoubtedly a better 
understanding will come about in due season ; and in 
the meantime the experimenters do not seem inclined 
to wait until the doubters are all silenced. The work 
goes merrily on, and the outlook is bright. The few 
examples already presented will perhaps enable one 
to see the general character of such experiments and 
the leverage they offer for prying into the recesses 
of the mind. In the later chapters there will be op- 
portunity to become further acquainted with the prac- 
tical uses of this quantitative work. 

1 Cattell, " Presidential Address " [on the history and value of experi- 
mental and quantitative work in Psychology], Psychological Review, 
March, 1896. 



CHAPTER IV 



THE EVIDENCE FOR UNCONSCIOUS IDEAS 



The problem 
appeals to 
the emotions, 



since it 
touches our 
most varied 
interests. 



The question of the existence of unconscious men- 
tal states is a difficult one to discuss with philosophic 
calm. Cold and abstract as psychology may appear, 
it has its own schisms and heresies, its own emotional 
problems, the answers to which determine whether 
one shall be numbered with the orthodox or with the 
wayward. 

In the first place the recognition of unconscious 
ideas savors strongly, at the present time, of psycho- 
logical Aberglanbe, — of thought-transference, of spir- 
itistic communications, and all that goes with the 
term " psychical research." Moreover, there seems 
to be an intimate connection between the doctrine of 
the unconscious and that of pessimism. The Oriental 
philosophies incline to both. Consciousness, accord- 
ing to most eastern thinkers, is the source of all evil, 
and blessed Nirvana is to be attained only by a return 
to the reality of life, which is unconscious. Amongst 
us such a view is expressed in Wagner's Tristan 
und Isolde, and is worked out in philosophic detail 
in the writings of Von Hartmann. Finally the doc- 
trine seems to strike at the very roots of psychology 
itself. There has already been occasion to speak of 
the role which introspection plays in the study of 

66 



Evidence for Unconscious Ideas 67 

mind. All the work in psychology, whether it be 
physiological or comparative or experimental, rests 
ultimately, as was said, on the validity of this intro- 
spective method. But if we were once to admit the 
existence of mental processes which elude the keenest 
self-observation, it would appear that introspective 
evidence were no longer decisive and that there were 
room in psychology for all manner of vain guess- 
work and imagination. It seems to unsettle the 
foundations of the faith, and those who have at heart 
the interests of the work must ward off the thought 
in very self-defence. The notion of the unconscious 
is consequently a source of anxiety to the conserva- 
tives, and even to some who, like Professor William 
James, have a radical strain in them. To his mind, 
this doctrine is " the sovereign means for believing 
what one likes in psychology, and of turning what 
might become a science into a tumbling-ground for 
whimsies." x 

Because of these wider connections of the ques- 
tion, it is well-nigh impossible to keep our judgment 
uninfluenced by our sympathies. Our warm blood 
compels us to have some preference as to where the 
truth should lie. Persons especially interested in the 
"borderland" of mind will, perhaps, find it difficult 
to tolerate a doubt as to unconscious phenomena; 
while those who have cast in their lot with a critical 
psychology, or who feel that the philosophy of the 
unconscious, with its accompanying pessimism, puts 
an end to morals and religion, will be apt to harden 
their hearts at the bare mention of the word. 

1 James, The Principles of Psychology, Vol. I, p. 163. 



68 



Experimental Psychology 



Perhaps none of us, then, may be unbiassed ; and 
yet, for the very reason that the question does lead 
out into the deeper interests of life, we cannot afford 
to neglect it. We must review the evidences, and 
especially the experimental work, that bears upon the 
case. 



The uncon- 
scious in psy- 
chology 
seems to 
many a self- 
contradic- 
tion. 



Leibnitz and 
the uncon- 
scious. 



Have we any reason to believe that there are aspects 
of experience of which we are not directly conscious ? 
In regard to the physical world, it seems intelligible 
enough that there should be things that no one has 
ever seen — stars too dim to affect our sight, bits of 
matter too small for our microscopes to reach. But 
at first sight at least, it seems impossible that there 
should be anything analogous to this in the mental 
world. For does not the very essence of what is 
mental lie in its being consciously before us ; are not 
its esse and its percipi identical ? Lotze has asked us 
what a pain would be which nobody felt; and the 
absurdity which attaches to such orphaned sensations 
would appear to belong to any mental fact which 
nobody could observe. To many the unconscious 
has always seemed a self-contradictory notion, like a 
square circle or warm ice. 

Yet in spite of the difficulties that beset such a 
conception, and of its mystic air, especially at the 
present day, it has had its sponsors among the most 
penetrating thinkers. It was originated, in fact, by 
Leibnitz, who certainly gives an impression of intel- 
lectual health and balance. The reader will recall 
in Carlyle's " Frederick " the remark of Queen Sophie 
Charlotte : " Leibnitz talked to me of the infinitely 



Evidence for Unconscious Ideas 69 

little; mon Dieu, as if I did not know enough of 
that." This thought of the infinitely little, which is 
the kernel of his mathematical discovery of the in- 
finitesimal calculus, was also given by him a psycho- 
logical application. According to his view, there are 
infinite degrees of mental life, from clear and perfect 
intellect, through consciousness that is like a dream, 
down to that of creatures existing as in a swoon or 
dreamless sleep. And since each creature is the 
world in miniature, — a mirror of the universe, — 
and since each recapitulates the whole series of crea- 
tures below it, we find in each human mind a scale 
of mental gradations corresponding to the scale of 
creatures : clear thoughts, obscure and dreamy im- 
pressions, and finally those that lie below the level of 
consciousness, too faint and confused to be perceived. 
These last he calls " minute perceptions " — what we 
should perhaps designate as subconscious or sublimi- 
nal ideas. To use his illustration, we hear in the 
distance the roar of the sea, produced by the sound 
of the separate waves. Each individual wave must 
produce in us some subconscious effect; for if the 
effect of each wave were zero, we could never ac- 
count for the actual roar we hear. It cannot of 
course be made up of a number of zero quantities ; 
it consequently must consist of a host of impressions 
exceedingly minute. 1 

I shall not attempt to trace the history of this Present-day 
thought since Leibnitz's day. It was caught up and f t vl ^ a enc r e in 
passed along to our modern psychology, where it has 
found lodgement even amongst many who give little 

1 Leibnitz, Opera Philosophica, ed. Erdmann, p. 197. 



7° 



Experimental Psychology 



" Alterations 
of personal- 
ity." 



Evidence 

from 

memory. 



recognition to any save our sober, common mental 
phenomena. Nor can we well consider more than a 
few of the varied arguments by which this view is 
supported in our time. Those who ardently believe 
in unconscious mental operations find evidence for 
them in almost every act that we perform : in our 
instincts, in our habits, in the short-circuiting which 
takes place at times in association, as well as in the 
common operations of sense. But the main em- 
phasis is laid on certain derangements of mind, par- 
ticularly on those strange lapses of memory by which 
whole regions of a man's experience pass from view, 
accompanied as this often is by an equally strange 
return of long-forgotten portions of the past. In 
extreme cases this leads to the so-called mutations of 
personality, somewhat as Stevenson has portrayed 
them in his " Dr. Jekyll and Mr. Hyde." Such 
phenomena, in connection with similar facts that 
develop in the hypnotic state, are now made much 
of as testimony for a subconscious life. Cataclysms 
of this kind, it must be confessed, put psychology to 
the test ; its present system seems hardly able to sup- 
port such strange occurrences. 

And yet, if we could but rid ourselves of the 
blinding effect of custom, the commonest act of for- 
getting or of recollection would not seem one whit 
less mysterious than these other more striking phe- 
nomena. To say that the facts of double or of multi- 
personality are but morbid exaggerations of processes 
we perform every day, of course does not explain them, 
but it at least puts us in a position to see that, as far 
as the reality of an unconscious stratum of experience 



Evidence for Unconscious Ideas 71 

is concerned, we can as well infer it from the one case 
as from the other. The fact that to-day I can recall 
experiences which had faded away during the night, 
and that in the dream state the mind of the most staid 
of us may drop its usual contents and live for hours 
in a mental whirl of dime-novel adventure, is just 
as good or bad evidence for unconscious ideas as the 
fact that Krafft-Ebing's poor patient lima S. could 
sing Magyar songs and secrete articles while in an 
abnormal state of mind, and know nothing of these 
acts until the same state was reinduced. 1 

Where were the experiences that they could com- what 
pletely disappear and yet be recalled when the hyp- fo r c °™^° 
notic condition was resumed ? Likewise we may ask, ideas ? 
Where are our waking thoughts, our scruples of 
conscience, our pride and prejudice, that we can dis- 
miss them in our dreams and yet find them awaiting 
us when we drop our play character and return to the 
serious concerns of life ? In all these cases there is 
a lapse of ideas from consciousness, and yet, evi- 
dently, some kind of persistence of them since we 
again meet them at a later date. The readily sug- 
gested explanation is that in the interim these ideas, 
as ideas, continue their existence in some subcon- 
scious limbo where they await their recall. 

Such a doctrine, however, appeals more strongly ideas are 
to the imagination than to the intellect. Ideas and ^substan- 
experiences are not stable objects that can be laid tiai things. 
away on our psychological shelf. They are processes, 
or acts, of the mind, and are as perishable as the acts 

1 Krafft-Ebing, An Experimental Study in the Domain of Hypno- 
tism, tr. by Chaddock, New York, 1896, p. 59. 



7 2 



Experimental Psychology 



They may be 
reenacted, 
but are 
never lit- 
erally pre- 
served. 



But may not 
this activity 
continue sub- 
consciously ? 



The lack of 
evidence for 
this. 



of the body. We can in either case perform the act 
again and again, and can add to it the further act of 
recognizing that it is something that we have done 
before. But it is as difficult to believe that the 
mental process, as mental process, can be stored up, 
as it would be to believe that the present movement 
of my arm is a reincarnation of the identical arm 
movement I performed an hour ago, which in the 
meantime had continued its existence in some inter- 
mediate state. 

But this might be said to beg the whole question. 
Granting that our ideas are not solid bodies that can 
be kept in storage, but are mental acts which exist 
only while they are being performed, may not the 
continued existence of a forgotten idea be conceived 
as an endurance, in some way, of the mental activity 
of which the idea consists ? The survival of an idea 
in the subconscious state would thus be intelligible ; 
it would be but the continuation, in a low degree, of 
the activity which in consciousness is clear and above 
board. The recollection of experiences would then 
be like the sudden brightening of a fire that had all 
the while been slumbering but not extinguished. 

As a mere matter of conceivability perhaps no fatal 
objection could be raised to such a view. Buried in our 
experience there may be such smouldering coals. But 
what evidence have we that such is actually the fact ? 

It is sometimes assumed that the recurrence of an 
idea is of itself sufficient evidence of this low per- 
sistent activity during forgetfulness ; 2 that there must 

1 Cf., e.g., Platner, Philosophische Aphorismen, ed. 1784, Vol. I. 
p. 103. 



Evidence for Unconscious Ideas 73 

of necessity be this uninterrupted life of the idea to 
serve as a kind of bud out of which the full-blown 
idea may again develop in consciousness. But if we 
cling resolutely to the notion that ideas and memories 
are not things or organisms, then it is clear that the 
revival of a mental image no more presupposes the 
continuance of the selfsame idea in low intensity 
than the recurrence of the movement of my hand 
requires that during the time when the hand seems 
to be at rest it shall all the while be rehearsing in low 
degree the motion which is later to be performed in 
full. If a physical movement can recur after an 
absolute interruption, why may not a mental process ? 

At first there may seem to be an unanswerable Thepersist- 
objection to this view. If each of our thoughts, no ^f u a e s " ce 
matter how often recurring, is an absolutely new 
creation, and our former experiences do not really 
endure, how is it that these former experiences exert 
such a vital influence upon our present thoughts ? 
As an actual fact, we find that the judgment we now 
make, the things that we desire, the scenes that we 
can imagine or recall, are moulded by the experiences 
of former days. Our whole outlook is colored by 
these past impressions and ideas. Does not this show 
that, whether we recall the past or not, we cannot 
sever ourselves from it, and that somewhere beyond 
the horizon of consciousness these thoughts and 
images must still exist and exert their influence even 
within the circle of our present ideas ? 

But such a theory does not in the least help us to 
understand the facts, but is rather a hindrance. In 
the case of the body there is a similar state of things 



74 Experimental Psychology 

to be explained, and any argument like this one 
which is so alluring in the mental realm would seem 
sheer nonsense or mythology. For in our physical 
does not conduct we notice that our acts of yesterday influ- 
continuance ence our rnovements of to-day. In trying to swim, 
of ideas. you find that it makes a difference whether you begin 
as a novice or have grown accustomed to the stroke. 
So the tricks of voice or of gait that we uncon- 
sciously imitated years ago, show unmistakably in 
our present physical behavior. But we should never 
think of ascribing this behavior to the literal pres- 
ence of those older acts, forming some kind of unseen 
aura around us and exerting a living influence upon 
Whatpersists our present functions. We should say, rather, that 
isthedisposi- ^ f ormer ac t s themselves are dead and gone, and 

tion to cer- ° ' 

tain acts. what remains is not even a pale image or copy of 
them, but that the person in enacting them formed a 
habit or disposition 1 by which such acts could as 
often as he pleased be reenacted, but never literally 
preserved. 

Something like this is certainly the simpler and 
more reasonable way to explain the apparent per- 
sistence of our ideas. Just how the "disposition" is 
to be understood would be a nice point to determine, 
and would take one far into the problem of the inter- 
connection of brain and mind, and into that, also, of 
Ways of con- psychic and physical causation. It is possible that 
ceivmgsuch ^ Q disposition might be conceived as something 

dispositions. r & o 

purely physical, as a persistent neural arrangement. 
This, however, is not the only way to conceive of 
habit in a psychological sense. We might believe 

1 Cf. Stout, Analytical Psychology, 1896, Vol. I, p. 21. 



Evidence for Unconscious Ideas 75 

that the mind of itself is capable of regular behavior, 
and that it does not owe this solely to the brain. 
Each mental act that we perform may well start or 
strengthen a purely mental disposition or trick of 
behavior, or bring about a combination of simpler 
mental habits already formed. The disposition would 
then be of the nature of a very specialized mode 
of activity ; it would mean that, given the suitable 
conditions, such and such special processes would 
follow. This mode itself, of course, would not be an 
unconscious idea or an imperceptible mental phenom- 
enon in the sense we are now considering. These 
mental habits could persist through comparatively 
long periods of disuse. Or, on the other hand, the 
occasions which call any special tendency into opera- 
tion might arise so rarely that the disposition itself 
would finally become obliterated. The conditions of 
memory and oblivion may thus be described in terms 
of mental tendency or mental habit running parallel 
to the neural tendency or neural habit by which we 
describe the brain side of the operation. And there 
are other forms of explanation should we wish to 
avoid even a tentative adherence to the doctrine that 
mind and body run parallel without any interaction 
whatever. 

We may safely conclude, therefore, that neither the The argu- 
phenomenon of memory nor any other recurrence of ™ entfrom 

x J J hypnotism 

ideas gives decisive evidence that there are acts of fails with 
our own minds that we are unable to observe. And that from 

memory. 

the argument from memory is really the kernel of 
the various arguments from hypnotism, alterations 
of personality, and the like. The only evidence for 



j6 Experimental Psychology 

unconscious ideas in any of these cases is that masses 
of ideas disappear and reappear, and as far as the 
logic of the case is concerned, it of course makes no 
difference whether the mass be great or small, impor- 
tant or unimportant. The alteration of large aggre- 
gations of ideas, such as occurs in serious disturb- 
ances of the mind, is therefore no more conclusive 
for subconscious mental events than are the facts of 
ordinary recall. 

The evidence The phenomena of automatic communication, how- 
fromauto- ever might seem to put the matter in a different 

matic writing ' ° sr 

and speech, light. The facts here are akin to those of alternate 
personality already referred to, with the difference 
that the contrasting personalities are now present 
simultaneously and can express themselves through 
different channels at the same time. An acquaint- 
ance of mine (a highly intelligent, although some- 
what neurasthenic, woman) could, while perfectly 
conscious, write automatically a fluent discourse that 
was often a surprise to her, in its contents, and even 
a shock to her sensibilities. Her hand seemed con- 
trolled by some independent mind. And Dr. Hodg- 
son, reporting experiments on the ever-interesting 
Mrs. Piper, says that when " Phinuit " is using un- 
interruptedly the medium's voice, her hand may all 
the while be carrying on some active communication 
as from another personality, 1 reminding one of the 
story of Caesar and his amanuenses. Flournoy's 
recently reported case of Helene " Smith " exemplifies 

1 See the Proceedings of the Society for Psychical Research, Vol. XIII, 
pp. 293 ct seq. 



Evidence for Unconscious Ideas 77 

the same thing. 1 While oral communications were 
being given, ostensibly from Mars, Flournoy was 
often able to obtain from the medium's left index 
finger comments and suggestions claiming to be from 
a mundane person named Leopold, alias Cagliostro. 
Such cases as these are different from the ordinary 
phenomena of forgetfulness. Different personalities, 
each with characteristic tricks of thought, are present 
at the same time. The consciousness itself seems 
cleft, and the one side appears to be ignorant of the 
occurrences in the other. 

The spiritistic interpretation of these things would The spirit- 
at once, of course, destroy their value as evidence for lstlc ™- th f 

' J psycho logi- 

unconscious mental action. If " Leopold" be regarded cai interpre- 
as a distinct mind using Helene's finger as a means tatlon# 
of communication, Helene's ignorance of his mental 
operations would not indicate that these processes 
were unconscious for him. It would simply be like 
our own ignorance of the present thoughts of the 
Emperor of Germany. But if we adopt the psycho- 
logical point of view, and regard the various " per- 
sonalities " in a case like Helene's as but different 
forms of the activity of the one person, then we must 
acknowledge that in the end they may favor the 
doctrine of the unconscious ; but since we are as yet 
ignorant of so many essential features in these abnor- 
mal phenomena, one may well hesitate to decide just 
what they do mean. We must wait for more light 
on the question whether the secondary personality's 
thoughts (if thoughts they be, and not some amazing 

1 From India to the Planet Mars (transl.), New York, 1900; cf. 
especially p. 120. 



78 Experimental Psychology- 

trick of the nervous system) are indeed unknown to 
the primary personality at the time when the expres- 
sive movements are taking place. For the most part 
we have to depend on the subsequent recollection of 
the person, and a negative result here is quite com- 
patible with a dim consciousness of the other person- 
ality's thoughts during their actual occurrence. It 
Parallels from may be as in our dreams, where a number of different 
sonaiities^" personalities occupy the stage at the same time, 
each representing a different point of view, each 
ignorant of the next move of his fellows, and yet 
there is nothing strictly unconscious nor any absolute 
cleft in consciousness, for all the dramatis persona 
are included in the larger single mind which is their 
theatre. 1 In Flournoy's report, it is extremely sug- 
gestive that when " Leopold " was presumably in ex- 
clusive possession of Helene's senses and reactions, 
and remarks were dropped by persons in the circle 
that would have offended the medium, she apparently 
did not hear them, but, after the trance, she showed 
by her conduct for weeks that the slighting words 
had not been lost upon her. 

The more cautious position, then, would be to re- 
gard these cases as due to parallel and relatively dis- 
connected streams of activity in the one mind. In 
all probability they are not beyond the range of self- 

1 A striking instance of this character occurred recently to a friend 
of mine. In a dream he was cross-examined as a witness in court. 
The counsel for the opposing side (by a series of questions narrated to 
me) gradually enticed him into a situation which ended in the wit- 
ness's immense surprise and confusion. There was here no mere recol- 
lection of a past occurrence, but rather a creation of a relatively 
independent personality. 



Evidence for Unconscious Ideas 79 

observation were the person in a condition favorable 
to introspection, or had he the training and interest 
needed for detecting the most obscure activities of 
his own mind. 

But passing from these abnormal phenomena, an Evidence 
entirely different line of evidence is suggested by J^^oid of 
what is known in modern psychology as the " thresh- sensation, 
old." An illustration will make clear the meaning 
of the term in this connection. If an ordinary tele- 
phone receiver and an electrically operated tuning- 
fork be suitably connected with a Du Bois-Reymond 
induction apparatus (Fig. 9), the telephone will re- 
peat the low drone of the fork with varying degrees 
of loudness according to the distance between the 
two coils of the induction instrument. Beginning 
with a loud note, we can gradually diminish the in- 
tensity until we reach a point where the sound is just 
heard, and then, as we pass this point, the note is lost. 
The limit between our consciousness of the impression 
and its absolute imperceptibility is what is called the 
threshold, — a warm domestic word, for which some 
have proposed to substitute the cheerless term "limen." 
The threshold, then, is the border of consciousness 
in general, beyond which is outer darkness ; and the 
illustration from the realm of sound is but a single 
case. Similar illustrations might be drawn from any 
of the senses, or even from our inner life of memory 
or imagination or feeling. 

In the particular example just used, when the sound 
crosses the threshold it apparently ceases to exist 
psychologically. But however that may be, we know 



8o 



Experimental Psychology 



The thresh- 
old seems 
to indicate 
impercep- 
tible sensa- 
tions. 



The analogy 
between 
brain and 
mind is here 
misapplied. 



that the physical stimulation — the vibration in the 
telephone — continues far below this point. Now 
many have thought that as the physical stimulation 
runs down a long scale of intensities below the point 
where the sound seems to die away, so, too, the 
psychic effect must likewise have a gamut of inten- 
sities below the threshold. In other words, the thresh- 
old here would be the point, not where the sound as 
a psychic phenomenon ceases to exist, but where it 
reaches an intensity too low for us to perceive it. 
Anywhere between the intensity of stimulation which 
we consciously perceive and an absolute zero of inten- 
sity there would be actual psychic effects of a sub- 
liminal or subconscious sort. This is practically 
Leibnitz's old argument from the roar of the sea re- 
appearing in modern laboratory guise. 

The argument, however, is clearly defective. When 
more closely examined the reasoning is found to be 
this : since mind and brain show so many analogies 
in their behavior, we may assume that the analogy 
continues throughout. Why may we not reasonably 
infer, then, that a nervous excitation which is too weak 
to be noticed is still accompanied by a dim psychic 
process — by an unconscious sensation ? This would 
seem to be but a consistent development of the prev- 
alent doctrine of a parallel between mental and ner- 
vous states. The difficulty, however, is that even if 
there should exist the closest analogy between the 
action of brain and mind, the fact of a subliminal 
stimulation would not in the least imply the exist- 
ence of a subconscious experience. For we must 
remember that by the stimulus we mean the outer 



Evidence for Unconscious Ideas 81 

physical irritant which plays upon the delicate organ 
of sense. The excitation, if it is to produce any psy- 
chic effect, must be strong enough to urge its way 
onward to the gray surface of the brain. If we knew 
that the subliminal vibrations of the tuning-fork really 
excited this particular region of the nervous system, 
then our parallelistic assumption would force us to 
admit that there must be some subliminal experience 
corresponding to this low degree of nervous action. 
But we do not know that the subliminal sound stimu- 
lates the brain at all. On the contrary, the tone may 
be imperceptible just because it is too weak to call 
forth a cerebral response. It cannot overcome the 
resistance along the way, and so its weak energy is 
dissipated. According to this view, the threshold of 
consciousness corresponds to the point where the 
brain itself ceases to act. There would thus be no 
subliminal brain-processes in this case at all, and 
consequently no ground for arguing the existence of 
subconscious sensations to correspond to them. For 
this reason the argument from the threshold and from 
the existence of subliminal stimuli, on which many 
persons from Leibnitz to H off ding have placed re- 
liance, is after all unconvincing. 1 

1 Cf. Hoffding, Outlines of Psychology, tr, by Lowndes, pp. 71 et seq. 



CHAPTER V 

FURTHER CONSIDERATIONS AS TO THE UNCON- 
SCIOUS 

Further evi- It is an axiom of logic that the collapse of any 
df s nc e S edof et numDer °f arguments decides nothing as to the truth 
or falsity of the view they were intended to support. 
So that we may still ask whether Leibnitz's doctrine is 
correct, even though the evidence he offers be not 
decisive. When we carefully distinguish between 
Leibnitz's notion and the popular view of unconscious 
ideas, the essential features of his conception seem 
to me to have solid support in the facts. Even after 
rejecting the greater mass of the evidence, as we 
have done, there is a remnant that cannot be dis- 
posed of in this way. 
ideas are But this evidence by no means indicates the exist- 

probabiy ence f unconscious ideas as currently understood. 

never uncon- J 

scious. Nor does it seem probable that Leibnitz intended 

anything of the kind. When he argues that, because 
the distant surf is heard, each wave must to some ex- 
tent affect us mentally, this need not mean that a sin- 
gle wave would arouse in us a subconscious idea of a 
wave, — a picture of undulation and blowing spray, 
such as is called up when we hear the sound near by. 
Psychologically speaking, there is a vast difference 
between hearing the low sound produced by a distant 
breaker, and hearing it as a breaker. In the latter 

82 



Further Considerations $3 

case we not only catch the faint sound, but its full 

meaning. It means to us sea and sand and salt air, 

a particular curve and play of color — all of which 

is not auditory at all, but is merely suggested by 

the auditory impression. The idea of the wave is 

thus a highly organized affair, and there is little 

reason to believe that any such complicated mental 

process takes place beyond our immediate observation. 

But that there are relatively bare auditory impres- But relatively 

sions, stripped of all those associations which raise ^aresensa- 

' rr tions perhaps 

them to the dignity of an idea, — too faint perhaps exist imper- 
to arouse their usual associates, certainly too faint to ceptl y * 
be distinguished against the vague background of 
other sensations, — that there are imperceptible 
occurrences like these, in the psychic realm, there 
seems to be good reason to believe. To call them 
unconscious ideas prejudices the case ; they had bet- 
ter be termed imperceptible events or imperceptible 
phenomena. 

What seems to me satisfactory evidence of their Evidence 
existence comes from a large body of experiments from ex P e "- 

° J r ments in dis- 

which measure our accuracy of distinguishing im- crimination, 
pressions. In every kind of experience we find that 
there is a limit to our power of discerning differences. 
Two lights may be of different brilliancy, but if one 
of them be not at least y^ brighter than the other, 
they seem to be the same. Two musical notes whose 
wave-rates do not differ at least a fifth of a vibra- 
tion a second, seem to the most delicate ear to be of 
identical pitch. Similarly, odors or tastes or touch 
sensations, or any occurrences whatever, can be dis- 



84 Experimental Psychology 

tinguished only so long as the difference between the 
impressions is of a certain amount. There is a thresh- 
old here not unlike the one already considered, except 
that it marks the point, not where sensations disappear, 
but where a difference between them disappears, the 
sensations themselves remaining clear and prominent. 
We found that the existence of a subliminal stimula- 
tion was no evidence that there are subliminal sensa- 
tions ; what must we now say in regard to a difference 
which cannot be felt ? Shall we say that an imper- 
ceptible difference in the mental field is not a differ- 
ence at all ; that the very backbone of a mental fact 
is the way it feels — its esse is its sentiri ; and that 
there is no real difference between psychic phenom- 
ena until the difference itself is felt ? No answer 
can be given offhand. It is quite conceivable that 
two different facts in the outer world — two weights, 
for instance, one of 100 grammes and another of 
102 grammes — would produce in us identical expe- 
riences, identical feelings of touch. The difference 
might be lost somewhere in transit between hand 
and brain, or if it actually reached the brain, there 
might be no corresponding difference over on the 
mental side. 

impercep- There is good evidence, however, that although we 

cannot perceive a distinction here, a mental difference 
really exists. If we compare 100 with 102 grammes, 
we find that they give absolutely indistinguishable 
intensities of pressure; so, too, if we compare 102 
grammes with 104. If impressions that feel alike 
really are alike, then the first is identical with the 
second, and the second is identical with the third; 



tible differ- 



Further Considerations 85 

consequently, the first must be identical with the 
third. As a matter of fact, however, the first and 
third weights are under suitable conditions clearly 
distinguishable. 1 And from this we may assure our- 
selves that the sensations arising from 100 and 102 
grammes are really different, although the difference 
is imperceptible. For if they were identical, they 
would behave alike ; they would be either equally 
distinguishable or equally indistinguishable from 104, 
whereas they are not; we find that one can be dis- 
tinguished from the pressure of 104 grammes, while 
the other cannot. The addition of 2 grammes to 100 
is imperceptible, but it produces nevertheless a real 
alteration of the mental state. But of course such 
imperceptible gradations in experience are not con- 
fined to this single realm of touch. The same evi- 
dences and the same argument could be repeated in 
regard to a wide variety of experiences, — in regard 

1 Such small differences are clearly perceived when an immediate 
and instantaneous change is made from the lower to the higher weight 
(though not when passing in the reverse direction), after the manner 
described in my " Ueber die Wahrnehmung von Druckanderungen bei 
verschiedenen Geschwindigkeiten," Philosophische Studien, Vol. XII, 
p. 531. The average threshold for increase for ioo grammes was there 
found to be 2.5 grammes. 

An additional illustration of a difference in sensations that is real 
but imperceptible could be found in the fact that the difference between 
two successive impressions becomes clear when we shorten up the 
time-interval between them, although with a longer interval the two 
impressions seem identical. The mere change of the interval cannot 
be supposed to produce the difference of intensity; it merely makes it 
apparent to us by allowing the comparison to be more exact. With 
the longer interval between the impressions, there is consequently a 
real difference that we cannot perceive. 



86 



Experimental Psychology- 



No assump- 
tion here as 
to the rela- 
tion of ner- 
vous to 
mental 
action. 



The " abso- 
lute " and the 
" discrimina- 
tive" thresh- 
olds are iden- 
tical. 



to sight, hearing, temperature, pain, and the like. 
Unaided self-observation might lead one to acknowl- 
edge here only considerable differences without inter- 
mediate steps. But the experimental evidence goes to 
show that nature makes no leaps. In all these fields 
there are infinite gradations of intensity and also of 
quality that are real, although they entirely escape 
our observation. They are, to use Leibnitz's phrase, 
petites perceptions, of whose existence immediate in- 
trospection gives no hint. Such facts as these seem 
to me to compel us to admit that the mind is wider 
than the portions we can directly perceive. And the 
great advantage of such evidences as these is, that 
they do not require some questionable assumption 
such as that there is a complete analogy between 
mind and brain, or that stimulus and sensation run 
exactly parallel courses. All this is left an open 
question, and the decision of it either way does not 
affect the present evidence in the least. 

From the position thus gained we may return to 
the question of subliminal sensations, and point out 
more clearly what the probabilities are. 

The reader will recall the two kinds of threshold 
mentioned some moments ago, — the threshold where 
a sensation fades completely away, and the thresh- 
old where two impressions, although clear and 
strong, cease to be distinguishable. It is customary 
in psychology to draw a sharp line between these 
two kinds of phenomena, and to say that the disap- 
pearance of a sensation is quite different from the 
fading out of a difference between two sensations. 
In all probability, however, this is a mistake, and the 



Further Considerations 87 

two facts spring from the same source. The point 
at which a diminishing sensation seems to die away 
is probably not where its intensity becomes zero, but 
is merely the point at which it is no longer distinguish- 
able from the nebulous background of sensations 
that are always with us. A particular impression 
must have a certain appreciable strength of its own 
to cause it to stand out from this dim confusion, 
arising in part from the mere circulation of the blood 
in the various organs of sense. The low murmur of 
life, as from a great city, is always within us, and a 
weak sensation may be lost from view merely because 
it is not sufficiently different from the host of other 
weak sensations present at the same time. As fur- 
ther experimental evidence which directly favors this 
view, we find by actual test that all sensations feel 
more and more alike the weaker they are. A person 
blindfolded cannot unerringly distinguish between the 
soft contact of wool and a gentle glow of warmth near 
the skin. 1 And careful observers will not infrequently 
be in doubt whether an exceedingly minute change 
of pressure on the skin is of sound or of touch. 2 It 
seems probable therefore that what we call the abso- 
lute threshold — where sensations seem to fade away 
— is but a special case of the general fact that 
differences must be of a certain amount before we 

1 See Moleschott's Untersuchuvgen zur Naturlehre, etc., Vol. VIII, 
p. 393, where Fick reports Wunderli's original experiments. His obser- 
vations are readily verified. 

2 This I have found to be the case with several good subjects when 
a slight noise occurred at the moment when a barely perceptible change 
of pressure was expected. See " Ueber die Wahrnehmung," etc., 
Philosophische Studien, Vol. XII, p. 547. 



88 



Experimental Psychology 



The exist- 
ence of im- 
perceptible 
sensations 
now seems 
better sup- 
ported. 



Direct evi- 
dence of 
their exist- 
ence and 
force. 



Effect of 

unseen 

shadows. 



can perceive them. A pressure or any other experi- 
ence must possess some appreciable intensity if we 
are to recognize it in the chaos of other sensations so 
like it. As soon as we can no longer discern it we 
feel that it is gone, but in truth it may still exist 
through many degrees of strength before it utterly 
passes from the mind. The limit to our power of 
distinguishing differences, taken in connection with 
the general similarity of weak sensations, leads one 
consequently to believe that these simpler mental 
processes do actually descend to a low and dim 
region where introspection cannot follow them. 
They are subliminal, and yet they are still in the 
mind. Let their strength be still further reduced, 
and they cease even this shadowy life. The existence 
of subconscious sensations, which could not well be 
inferred from the fact of subliminal stimulations, thus 
appears quite reasonable when approached from the 
side of these imperceptible differences. 

But if this were all, there would perhaps be a 
certain theoretical interest in the fact that experience 
could exist at so low an ebb, but we might be inclined 
to believe that the existence of imperceptible phe- 
nomena was of no importance for our mental life. The 
experimental work goes to show, however, that these 
obscure and even imperceptible variations are impor- 
tant factors in processes which we can perceive. They 
affect the action from behind the scenes. Our con- 
scious space-perception, for instance, may be altered 
by these utterly elusive elements. Some recent ex- 
periments by Dunlap show that lines so drawn as 
to produce an illusion of distance, may influence our 



Further Considerations 89 

estimate of space even when these lines are quite 
imperceptible. 1 In the Miiller-Lyer diagram, shown 
in Fig. 10, the small angles on the horizontal line 
make the two halves seem of different length. In 
the experiment mentioned, such a horizontal line was 



< 





Fig. 10. — The Miiller-Lyer figure. 



distinctly visible with its segments marked by short 
cross-lines (Fig. 11); the small angles of the Miiller- 
Lyer figure, however, were made by shadows from a 
light so faint that the observer could not tell whether 



B 



FIG. 11. — The dotted lines show the different arrangements of shadows 
that — even when they are invisible — continue to influence one's 
judgment. 

the angles were thrown as in A or as in B of this 
figure, nor whether in fact any angles were thrown 
upon the line. And yet under these circumstances 
the run of judgments in a long series of experiments 

1 Dunlap, " The Effect of Imperceptible Shadows on the Judgment 
of Distance," Psychological Review, Vol. VII, p. 435. 



90 Experimental Psychology 

indicated that the apparent length of the segments 
was altered according as these subliminal shadows 
were cast in the one way or the other, or (unknown 
to the observer) were not cast upon the line at all. 
Experiments A further and final example might be drawn from 

ni^sounds 1 " the effect of sounds u P on tne attention. We have all 
had our attention caught by the sudden stopping of 
a clock, although we could not otherwise have told 
whether it had been ticking or not. It may be that in 
this case we are conscious of the beats, but are simply 
more attentive to other things. But under different 
conditions the facts seem somewhat less ambiguous. 
Suppose a person is in a silent room listening in- 
tently to a low sound in a telephone, growing fainter 
and fainter, after the manner a]ready described 
(p. 79), until finally he is unable to hear it, strain his 
ears as he may. Yet even when the observer is posi- 
tive that he has lost the sound, if the imperceptible 
note be cut off completely, the subject will often 
notice the change. A void suddenly opens up in the 
auditory field which had already appeared a perfect 
blank. At other times, when the subliminal sound is 
cut off, what we are struck by is not so much the dis- 
appearance of the sensation itself, but, rather, a sud- 
den and subtle change of mood — a feeling of relief, 
as if the attention could now be honorably recalled, 
since the tenuous nothing for which it had been 
searching had been definitely reported dead. If this 
correctly describes the mental state, what we feel 
under these particular circumstances is not the de- 
parture of the sound itself, but a conscious effect of 
that departure, a sudden unaccountable relief. It 



Further Considerations 91 

would imply that the sound, imperceptible though it 
was, could still muster up strength to tease and elude 
the attention, until the actual stopping of the sound 
brought the strain to an end. There is, of course, 
nothing decisive in this alone ; it might be explained 
without assuming that the sound was there at all. 
For it is not always necessary to have a present 
experience of a thing in order to note its departure. 
Its mere physical presence may produce a condition 
of nervous equilibrium for which there is no positive 
psychic counterpart, while its sudden interruption 
might disturb this status quo sufficiently to give a 
slight but positive mental shock. But on the whole 
the explanation I have suggested seems to me the 
more probable, and so I offer the experiment as 
supporting the doctrine of imperceptible mental 
events. 

And as in this case, so I might say of all the evi- Character of 
dence offered, — that alternative explanations are pos- asshole* 
sible. Brain-processes or mental facts may yet be dis- 
covered which would put all our evidence in another 
light. And to entertain even the possibility of other 
explanations has a certain value ; it serves as an en- 
courager of hesitancy, and brings one to his senses 
who would claim that he can demonstrate the case. 
He may flout the alternatives as he pleases ; but if 
there is an alternative even of the most improbable 
sort, he must change his tone from absolute proof to 
preference and probability. So that the facts I have 
presented are given with the feeling that they are 
gently persuasive merely ; they invite rather than 
compel our belief. 



02 



Experimental Psychology- 



Concluding 

interpreta- 
tion of the 
results. 



What seems to me the meaning of these evidences 
is perhaps already clear. They lead us to a mean be- 
tween two indefensible extremes. On the one side 
is the teaching that all the events in the mind occur 
in full light, and that the natural history of the mind 
must confine itself to those occurrences which a trained 
introspection can report. Experimental results, how- 
ever, draw us away from such a view ; they show us 
that it cramps the facts. At the same time they do 
not carry us to the opposite extreme — that of uncon- 
scious ideas as so often understood. That is a mystic 
doctrine according to which we each have an un- 
visited psychological lumber room (to use Mr. Pod- 
more's expression), with its accumulation of forgotten 
experiences, a room which, though unvisited by our con- 
scious self, is occupied by an unconscious self, busied 
with all manner of unconscious devices to accomplish 
unconscious ends : getting subliminal pleasures and 
disappointments out of its quiet, subliminal life. Here 
the unconscious mental life is conceived as filled with 
much the same kind of things as is our conscious life, 
the difference being that it is unconscious. Our re- 
searches lead us into no such extravagance as this. 
The results are not in favor of unconscious ideas, 
but rather of certain unconscious materials out of 
which conscious ideas arise. They lead us to ac- 
knowledge that there are indiscernible occurrences 
in the mind of a very definite and non-mythical char- 
acter, comings and goings of dim sensations, subtle 
variations in the strength and quality of certain con- 
stituents, which, minute and imperceptible though 
they be, are sufficient to destroy the equilibrium and 



Further Considerations 93 

produce a transformation of the whole mental state. 
The experiments, though they carry us to no extremes, 
do open up a new and most attractive field of research. 
They assure us that we can go a little below the sur- 
face, a little into the shadows of our experience. 

And now a word as to James's indictment 1 that all Nodangerto 
this is the " sovereign means for believing what one ^ h t ^ v 
likes in psychology, and of turning what might be- conscious 
come a science into a tumbling-ground for whimsies." 
One must acknowledge that there is a certain his- 
torical justification for James's remark. The doctrine 
of imperceptible phenomena to-day keeps bad com- 
pany ; it seems to have an affinity for minds that 
throw logic and the canons of induction to the winds. 
But we must beware of psychological exclusiveness, 
and not reject a truth because we feel aversion 
toward the kind of men who most readily accept it. 
And, after all, there is nothing more anarchic 
in this doctrine than in the notion that the phys- 
ical world has its imperceptible events. What a 
tumbling-ground for whimsies the recognition of an 
invisible energy like electricity or magnetism has 
supplied ! Only some weeks ago a deluded mortal 
was expounding to me how insanity could be drawn 
off from one person and injected into another by 
means of magnets. But one does not on this account 
feel that scientific procedure is at an end, once we 
admit what leads to such vagaries. Dreaming and 
knowing are as distinct after such admissions as be- 

1 See p. 67. Professor James in his subsequent work has become 
more friendly to the unconscious. Cf. e.g. his Varieties of Religious 
Experience, 1902, pp. 233 et sea. 



94 Experimental Psychology 

provided the fore. Because immediate sensible confirmation is dis- 
attTtude°in pensed with, we need not think that all the ordinary 
regard to the rules of evidence are abrogated and that we are free 
maintained* to helieve what we please. There must still be sen- 
sible evidence for whatever is proposed in this field; 
but since the evidence must now be circumstantial, 
rather than direct, all the more need of putting it 
mercilessly to the test, of holding before ourselves 
alternative explanations, of weighing and sifting until 
we can convince ourselves that there is more reason 
to believe that some unseen factor is at work than 
that the causes of the phenomena are among the 
events we can observe. Neither credulity nor hard- 
ened unbelief will serve us here ; we must demand 
the evidences, but respect them when they come. 
Such an attitude seems hardly to endanger the prog- 
ress of psychology, but rather gives an added assur- 
ance that the study will progress. 



CHAPTER VI 

ILLUSIONS AND THEIR SIGNIFICANCE 

Our illusions of perception seem contrived for the illusions are 
special purposes of psychology, — as if Providence, s^ceto'the 
foreseeing the natural perplexity of the student of psychologist, 
mind, had sent them for his comfort. For nothing . 
else reveals as they do the manner of the mind's 
activity. As long as our mental operation is perfect, 
and does not color or distort the facts, the mind is 
like some subtle medium that permits us to see all 
things, while remaining itself unseen. But when once 
the mind's action becomes troubled so that it tinges 
and deforms the scene, then our psychic processes 
themselves come to view and we are enabled to note 
their form. For psychological purposes, therefore, 
illusions might perhaps be compared to the deli- 
cate, artificial stains which are of such help to those 
who use the microscope ; the dyes discolor the object 
and render it in a way untrue ; but only to bring 
out with tenfold clearness the hidden niceties of its 
structure. 

For this reason the study of illusions occupies a 
prominent place in psychological work. Whatever 
may be one's field of investigation, he must constantly 
attend to the illusions there ; and not with a purely 
negative and hostile attitude toward them, as might 

95 



9 6 



Experimental Psychology 



Their range 
and provi- 
sional classi- 
fication. 



I. Illusions 
from spon- 
taneous sen- 
sations. 



perhaps be supposed — as if an experimenter wished 
to find them only in order to avoid them and free his 
results from error ; but rather does he welcome them 
as of positive service in throwing light on the prob- 
lem in hand. 

It is difficult to find a field of research where 
these distortions of reality do not occur. Our sense- 
perceptions — taste, touch, hearing, sight — are pro- 
verbially fallible. But they are by no means alone 
in this. Self-observation, also, gives us appearances 
opposed to the facts ; there are errors in our estimate 
of time; and memory inserts into the past various 
items that never occurred, or transposes the order of 
actual events. So that one is embarrassed by the 
very wealth of the materials here, and is forced to 
make an unusually exclusive selection to illustrate the 
more significant features of the subject. 

For the purpose in hand it will perhaps be best not 
to group illusions, as is frequently done, according to 
the special field in which they occur, as illusions of 
sight or of touch or of introspection or of memory ; 
but according to the general causes which produce 
them. Judged by the broader circumstances under 
which they arise, there are three provisional classes 
into which illusions may be grouped. 

In the first class we should include those illusions 
which arise from a certain perversity of the sense- 
organs in that they give us sensations by spontaneous 
action, not waiting for an excitation to come in from 
the outer world. Such is that subjective ringing in the 
ears which we sometimes hear, and perhaps also 
the faint mist which our eyes always give us even 




Fig. 12. — Apparatus for producing an after-image of motion, in 
direction the reverse of the original movement. 



Illusions and their Significance 97 

when in the darkest room, although this may be in 
large part due to an action of the brain. The visual 
field is never free from vague forms and colors not 
due to outer things — forms which persist in our sleep, 
and doubtless furnish much of the stuff our dreams 
are made of. In the case of the delirious and the 
insane, such images are possibly more intense, and 
when decked out by the morbid fancy, become the 
strange realities which people their world. 

Into this class fall also many of our illusory contrast 
effects and complementary after-images. In the eye, 
the stimulus falling on a particular place of the retina 
produces a temporary disturbance of the functions of 
neighboring parts; and even after it has ceased to 
play upon the nervous surface of the eye, some time 
is required before a perfect equilibrium is again re- 
stored. This is perhaps the cause of that illusion of 
motion we get after looking at a spiral like the accom- 
panying one (Fig. 12), made to revolve at a moderate 
speed ; when the spiral is stopped it seems gradually 
to draw in or expand — there is a viscid flow in a 
direction opposed to the original movement that the 
spiral seemed to have as the figure revolved. The 
same thing occurs if we look over the side of a mov- 
ing ship at the water rushing by ; the deck will then 
seem to glide slowly toward the bow of the vessel, 
or if we look long at a waterfall and then away to the 
cliffs, these move gradually skyward. It seems clear 
that all these illusions depend in the main on some 
disturbance in the sense-organ, an unusual behavior 
of the eyes or ears in these cases is at the bottom of 
the abnormal experience. 



98 Experimental Psychology 

Let us now pass to some examples of illusions 
which offer a certain contrast to those we have just 
been considering. 
11. illusions If two equal weights — each, say, 50 grammes — be 
attention SS ° concea l e d in boxes of quite different size, the weight 
in the large box will seem, when lifted, much lighter 
than that in the smaller box. And the amount of 
the illusory effect can be measured ; we may gradu- 
ally add to the weight in the larger box or take from 
that in the smaller one, until the two seem equal ; 
the addition or subtraction thus required to bring 
them to apparent equality gives us some idea of the 
strength of the illusion. In the case of boxes having 
the relative sizes given in the diagram (Fig. 13), I have 

often found that 
the weight of the 
smaller box must 
be reduced by 



( ) 



FlG as much "as 15 

grammes before it 
will seem equal in weight to the 50 grammes having 
the larger volume. The illusion starts from the expec- 
tation which the sizes of the boxes arouse. Experience 
has taught us that in general the weights of things 
increase with their volume. But the actual weight of 
the larger box is so much less than we anticipated, 
and so much less than we had prepared our hand to 
raise, that by contrast it seems much lighter than it 
otherwise would. It is underestimated, and for like 
reasons the weight in the smaller box is overestimated. 
A further illusion of similar psychological import is 
found in comparing the intensities of a number of 



Illusions and their Significance 99 

sounds coming in quick succession. When we listen 
to such a rapid series, say of clicks that are of equal 
strength, if they come neither too fast nor too slow, 
most persons cannot actually hear them as equal. 
Certain regularly recurring members seem slightly 
more emphatic than the rest, and the whole series 
falls into a subjective rhythm. We can interrupt this 
periodic emphasis and make it rest now here, now 
there, but fall somewhere it must ; the attention must 
glide over some beats and linger on others, and this 
subjective selection somehow tricks us into a momen- 
tary feeling that the favored impressions are the 
stronger. 

Under other circumstances the stress of attention, 
as is well known, deceives us in our estimate of time. 
A stretch of blank time marked off by an initial and 
a final stroke does not seem of the same length as an 
identical interval filled in with a number of succes- 
sive strokes. It will seem longer or shorter than the 
"filled" time, according to the actual length of the 
time with which we are dealing. But still more 
striking is the illusion which may occur as to the 
order in which impressions come. If we observe a 
rapid sequence of colors appearing at an opening in 
a screen, and a stroke of a bell be given in conjunc- 
tion with some single one of them, say, green, the 
place in the color series where the stroke seems to 
occur is usually not its true place in the series. We 
ordinarily locate the sound much too early in the 
series ; it will seem to come, perhaps, with a blue or 
a yellow that preceded the green. Why we should 
do this is not entirely clear ; the displacement is too 



IOO 



Experimental Psychology 



These are 
not ex- 
plained by 
"experi- 
ence." 



They show 
the interplay 
of mental 
processes. 



large to be accounted for by the lag in the photo- 
chemical process of the eye, so that the illusion is 
probably due to the unequal attention we give to the 
different members of the series. Our greater atten- 
tion to the sound seems to crowd aside the colors 
which appear at about the same time ; the stress 
upon the bell stroke gives it a prominence and tem- 
poral promotion over some of the colors, which for an 
instant are less attended to and consequently suffer 
a kind of eclipse. 

Phenomena of this kind do not spring from the 
sense-organs, nor can they be fully explained by ap- 
pealing to habit or custom or " experience." Experi- 
ence has not taught us that in the majority of cases 
sounds come early in a color series, or that succes- 
sive sounds really are due to causes which show a 
rhythmic rise and fall of energy ; nor has experience 
taught us that large bodies are usually lighter than 
small ones, but more often the reverse. These illu- 
sions, therefore, reveal a mental activity to some 
extent independent of mere custom brought about 
by experience ; they show that our mental processes 
interplay and modify one another — that our esti- 
mate of time, for instance, or our feeling of the 
intensity of a pressure or a sound is neither imposed 
upon us by sheer force of the outer facts ; nor is it, 
on the other hand, the result of a special and isolated 
psychic process whose only function is to mark the 
time or to perceive weight or sound. Men used to 
believe in a number of independent activities of 
mind. We had many separate faculties working like 
separate organs in the body, — a faculty of sight, 



Illusions and their Significance 101 

another of touch, of memory, of judgment, of atten- 
tion, and so on, — a view well represented in the old 
phrenology, where a special brain-tract was given 
over to the exclusive use of each of a score of psychic 
activities, from smell to " philoprogenitiveness " and 
reverence. Illusions show, on the contrary, how 
closely interlaced, how interdependent, our mental 
activities are; the errors spring from an intimate 
interplay of sensation and memory and attention and 
judgment. Our mental stress, our attention, our 
feeling of value, can cause the temporal order to be 
reversed ; there is, then, no sense of time in which 
attention and interest play no part. The weight-size 
illusion also shows how the different sides of mind 
conspire : expectation and images called up from pre- 
vious experience here crowd in upon the actual sen- 
sations, but instead of being able to make these 
sensations appear like themselves, they make them 
take on an entirely contrasting aspect. And the same 
occurs in the rhythm of equal sounds ; the intensity 
is affected by our subjective attitude toward them ; 
they are caught up and impressed by the general Evensensa- 
state of the mind. No sensation has an inviolate ; ionst J ke 

their charac- 

inner character which remains unaffected by the ter from their 
larger mental life. The connection, the significance [j^g tal SGt 
of impressions alters their very essence. The quality 
of the voice sounds different when we cannot under- 
stand what is said ; and colors in the face or in the 
landscape come out with surprising freshness if we 
see them reflected in a distorting glass or metal, or 
look at the scene with head bent, so that the recog- 
nition of objects is in some degree disturbed. The 



102 



Experimental Psychology 



meaning of sensations changes their pure sensa- 
tion quality. Each process is what it is because 
other things are what they are ; here, too, nothing is 
fair or good alone. The fiction of independent sensa- 
tions which by association make up our perceptions 
and ideas, the fiction of a number of separate 
faculties each with its exclusive field, — these go the 
way of the similar fictions in physics or political 
science, — the belief in a world constituted of inde- 
pendent atoms, or in a sovereign state arising by 
contract of free and independent persons. 



III. Illu- 
sions due to 
fixity of inter- 
pretation, or 
" custom." 



The final group of illusions would include, per- 
haps, the great mass of our familiar deceptive expe- 
riences: the change in the apparent distance of objects 
from us as the atmosphere changes in clearness, the 
vivid appearance of depth which the stereoscope 
gives, the circling of things about us when we are 
dizzy, the car-window illusion which makes our train 
seem to be in motion when a train beside us begins to 
move — all these and a hundred more have a certain 
common origin. These illusions, unlike the group 
just considered, are due to mental habit or custom, 
are due to the particular training which experience 
has given us ; and, having once learned our lesson, 
we proceed to apply it with mechanical regularity, in 
season and out of season. We stick to the mode of 
mental activity which we have found appropriate to 
the general run of cases. Thus ninety-nine times out 
of a hundred we find that the movement of the whole 
field of view from a car window is due to the motion 
of the car itself ; the habit of interpreting this expe- 





FIG. 14. — Aristotle's Illusion. 



Fig. 15. — Diagram to represent the 
psychological effect of the con- 
tacts in Fig. 14. 





FlG. 17. — The converse of Aristotle's 
Illusion. First form. 



FlG. 18. — Diagram of the psychologi- 
cal effect of the contacts in Fig. 17. 





FlG. 19. — The converse of Aristotle's 
Illusion. Second form. 



FlG. 20. — Diagram of the psychologi- 
cal effect of the contacts in Fig. 19. 



Illusions and their Significance 103 

rience becomes fixed, and thenceforth all movements 
of the whole field mean for us but this one thing, 
whether they actually arise from our movement or 
not. If the more usual way in travelling had been 
to sit still at a window and have something move the 
landscape outside until the right portion of the earth 
arrived, our illusion would have been the reverse; 
an actual motion of the car would then have felt 
like a movement of things outside our window. 

An excellent example of illusions of this class, and Aristotle's 
one, moreover, which permits of experimental varia- jf^J^J 
tion and reversal, is the familiar deception of touch, 
called Aristotle's illusion. If the index and second 
finger of the same hand be crossed and a pencil be 
placed between their tips, as in Fig. 14, we feel two 
pencils there instead of one. Here, again, the cause 
is found to lie in long training and mental habit. 
The parts of our fingers with which the pencil is in 
contact can usually be touched only by two separate 
objects with the two fingers lying between. The 
tactile impressions, being such as are customarily 
caused by two objects, are by force of habit inter- 
preted as two (somewhat as in Fig. 15), although a 
single object is now the cause. 

It is especially interesting that the converse of this 
illusion is also true ; namely, that an impression which 
is habitually due to a single object will be felt as a 
single object, even when, from the unnatural position 
of the fingers, it is now produced by two objects quite 
a distance apart. If two prongs of flexible wood or 
of wire be attached to a handle so that they can 
be manipulated together (Fig. 16), and they be so 



C=3 



104 Experimental Psychology 

adjusted that the crossed fingers lie between them 
and yet in contact with them both, as in Fig. 17, 
places on the skin can now be found which absolutely 
destroy the feeling of distance between the prongs ; 

they merge into one, and 
are felt as a thin strip 
running up between the 
crossed fingers (Fig. 18). 
Or again, if we move the two prongs to points on the 
skin which normally require three separate things to 
touch them at once, as in Fig. 19, the two strips are 
now felt as three (Fig. 20). The single principle 
holds throughout this varied illusion, that we inter- 
pret the impressions according to the causes which 
normally produce them. The sensations which usu- 
ally come from a single object are felt as a single 
object : the impressions which usually come from 
two objects are felt as two objects, however these 
impressions or sensations may, under exceptional 
circumstances, be produced. In this entire class of 
illusions, therefore, there is clearly present a process 
of interpretation, and the mode of interpretation which 
we adopt for all cases is that which experience has 
taught us is generally correct. The illusions them- 
selves arise because of exceptional cases not provided 
for in our general rule of interpretation. By sheer 
mental inertia we continue to interpret the exceptional 
cases as if they were regular, and so we go astray. 
Light on Nothing could better illustrate the way our minds 

normal per- wor k no t on iy under exceptional circumstances, but 

ception. J * 

also under ordinary conditions. Our illusions make 
clear the process of perception itself ; they show 



Illusions and their Significance 105 

how we perceive the outer world even when we per- 
ceive it correctly. We do not stand face to face with 
the outer facts and passively receive their accurate 
image. There is no direct and absolutely reliable 
intuition of things without. The world merely gives 
us a succession of impressions which of themselves 
have no single and inevitable meaning. Our sen- 
sations are more or less arbitrary symbols of the 
outer facts, and we must learn to read them. To The outer 
use Berkeley's figure, our sense-impressions are a w ° rld s P eaks 

J ° r a language 

language ; and, like any language, they must be 
gradually learned and are never entirely free from 
misunderstanding. Many of the signs are of doubt- 
ful meaning, and we must judge them as best we 
can. Here, of course, training, our previous experi- 
ence, our temporary preoccupation, the immediate 
surroundings or context, are what determine what we 
shall feel to be true in the particular case. But with, occa- 
nature at times runs counter to all our expectations. ^2'JJJ,, 
She uses a familiar expression in an unusual sense, ofexpres- 
and finds us totally unprepared. It is much as if 
some laborer, busied in a watch factory, were sud- 
denly to rise to poetry and sing the praises of the 
spring; his expression "spring" would produce on 
the minds of his stolid fellow-artisans an effect analo- 
gous to our illusions of experience. Their own par- 
ticular world would be too much with them, so that 
this rare and unaccustomed application of their term 
would be misunderstood. 

Now, in spite of these various sources of illusion — 
the perversity of the organs of sensation, the inter- 



io6 



Experimental Psychology- 



play of our several mental processes, and the inter- 
pretation of exceptional experiences according to a 
habit to which the general course of experience has 
trained us, — can we bring all these different causes 
under one common principle ? 

The more important illusions are clearly due to 
errors of interpretation. They are not justly to be 
called errors of sense ; the sensations are not at 
fault, nor has the organ of sense perverted the facts. 
The symbols or signs of external reality have simply 
been misunderstood. Here the illusions, we might 
say, are of intellectual rather than of sensory char- 
acter ; if we could arrive at their right meaning, 
no illusion would occur. But in two of the classes 
of deception, the symbols themselves do not seem 
to be misinterpreted ; they have been distorted, in 
the one case by the nervous organism, and in the 
other by our mental stress. These illusions conse- 
quently seem to stand in a group opposed to the 
others. 

And yet when we come to examine them closely, 
we can see that there is no fundamental difference 
here. Even the illusions that seem most clearly due 
to sense are actually from a higher source ; and if 
there were no error made in interpreting the im- 
pressions, the mere impressions themselves, whatever 
might be their character, could never produce illu- 
sion. Taken by themselves, they are sensations, 
ah involve a neither true nor false; they become true or false 
only when we begin to view them as signs of a more 
permanent reality. If we could keep from doing 
this, if we could keep from interpreting them, or if, 



The three 
groups of il- 
lusions are 
fundamen- 
tally alike. 



mismterpre 
tation 



Illusions and their Significance 107 

on the other hand, we could see them in every case 
in their proper relations, no illusions would occur. 

The difficulty is that in themselves our sensations 
tell us nothing of their origin ; they stand dumb 
before us and leave us to guess their secret. But 
since in the special senses more of the sensory impres- 
sions come from external than from internal causes, 
we find that it practically works best to fall into the 
habit of treating them all as from without. We take 
the course which suits the majority of cases, and so 
here, again, the illusion, even when it belongs to the 
class most intimately connected with the organs of 
sense, is at bottom due to custom or habit. 

We can conceive of two kinds of worlds in which Conceivable 
no illusions would occur. The one would be a world w ? rIds .„ 

where lllu- 

in which every impression of a particular sort arose sions would 
from one set of causes and only one. Here there si y™ pos " 
would be no ambiguity, and each occurrence would 
be read aright. It would be like a language in which 
every word was always used in an unchanging sense. 
The other equally illusionless world, if world it might 
be called, would be one where similar impressions 
came so rarely from the same causes, that no habit 
of interpretation could ever be formed. Alice's Won- 
derland gives some hint of what such a state would 
be. Each experience would feel like an absolutely 
unique event ; it would never indicate what was to 
come next ; no expectation would be aroused, and 
consequently there could be no mistakes. 

But in our actual world, a mixture as it is of order In this world 
and anomaly, illusions seem unavoidable. If we ^detect ttie 
could confine our mental life to bare sensations and errors. 



io8 Experimental Psychology 

their sensory associations (as some have erroneously 
believed we always do), if we could stop taking our 
sensations as indications of something more impor- 
tant behind them, there never would be any appear- 
ance contrary to reality. The oyster, the jellyfish, 
are probably under few illusions. But since we have 
developed to that condition where we are no longer 
satisfied with our surface impressions, but must always 
be asking what they mean, our hope lies not in less, 
but in more and better interpretations of them, in 
discerning truth and falsehood, in detecting illusions 
when they come. 

How are And so we must now consider the problem of dis- 

distin°uished tinguishing illusions from true perceptions. What is 
from true the psychological difference between them, and how 
perceptions can we j etect an illusion when it arises ? I have 

already pointed out the similarity of illusions and per- 
ceptions. In no case do we have an immediate, face- 
to-face acquaintance with the world ; on the contrary, 
we must interpret and arrange as best we can the 
mass of impressions which constantly arise. We in- 
evitably form some judgment of what they signify. 
So far the processes of illusion and of perception are 
alike ; they are both estimates of what the sensations 
stand for. 
is the differ- What is the difference between them ? One feels 
k^icai on?? 7 tem P ted to sa Y> with Sully, that the difference may 
be described as a logical one — perception being a 
kind of correct reasoning from the data or premisses, 
while illusions are fallacious inferences. 1 Much can 

1 See Sully, Illusions : A Psychological Study, 4th ed., p. 335. 



illusions and their Significance 109 

be said in favor of such a view. There is a remark- 
able similarity between perceiving a thing correctly 
and drawing a valid conclusion from given premisses. 
Our perception of a man, for example, might be cast 
into the following syllogistic form : — 

Major Premiss : All sensations having such and such 
definite characteristics are signs that a man is before me. 

Minor Premiss : Here is a group of sensations answering 
this description. 

Cone/usion: Therefore they indicate the presence of a 
man. 

This is in faultless logical form, and we might say 
corresponds to a true perception. 

But one becomes less confident that he can find in strictly, both 
the logical character of the act the difference between P e] ^ ce P t,on 

o and illusion 

true and false perception when he tries to cast an are fallacies, 
illusion also into syllogistic form. Suppose one of 
us to be laboring under an hallucination that a man 
is before us when in reality none is there. Expanded, 
the mental process might be stated thus : — 

Major Premiss : All sensations having such and such 
definite characteristics are signs that a man is before me. 

Minor Premiss : Here is a group of sensations answering 
this description. 

Conclusion : Therefore they indicate the presence of a 
man — 

the very statement which served to represent the 
correct perception. The mental process is as logi- 
cally consistent in the one case as in the other; con- 
sequently, so far as valid form is concerned, illusion 
and perception are absolutely indistinguishable. 



no Experimental Psychology 

The truth is, of course, that while the conclusion here 
in both cases is correctly drawn from the premisses, 
the major premiss is by no means universally true. 
We are not justified in asserting that the certain defi- 
nite characteristics referred to in our major premiss 
are the infallible sign that a man is present, since 
experience actually gives instances where this is not 
the case. The major premiss is false in both syllo- 
gisms, so that we have what the logicians call a mate- 
rial fallacy in every case of perception as well as of 
illusion. Or if we escape the material fallacy by re- 
arranging our premisses to read : — 

Major: Every real man gives me an impression of a 
certain definite character. 

Minor : Here is something which gives me such an im- 
pression. 

Conclusion : It must be a man — 

then the premisses are sound enough, but we have 
the fallacy of "undistributed middle," recognizable 
immediately when we say, — 

All gold glitters. 
This thing glitters. 
Therefore, it is gold. 

andareindis- And since the correct perception takes this fallacious 
by1ogic able f° rm q u ite as readily as does the illusion, we are not 

aided in the least toward an accurate statement of the 

difference between the two. 

But a flaw in the reasons we give for a proposition 

of course determines nothing as to its truth or falsity. 

We give bad reasons for many truths. In building 

up our experience from sense-impressions, then, we 



Illusions and their Significance 1 1 1 

fly in the face of formal logic. We jump at the truth 
from insufficient evidence. In other words, we take 
our chances, having found out by practical life that 
the risk of error is relatively small. 

But if logic cannot help us to distinguish true 
experience from deception, since both are condemned 
by the rigid canons of deduction, how can we dis- 
tinguish them ? 

A ready answer would be that our perceptions can illusions 
accord with the facts, while our illusions do not. be r( : c ° g ~ 

nized by 

According to this view, the processes themselves going direct- 
are not different ; we could never by an inner analy- ly to reallty ? 
sis of the mental act determine whether it was an 
illusion any more than we could take a photograph 
of an unknown person and decide by chemical analy- 
sis whether it was a good likeness or not. We must 
go outside the mental process and compare it with 
external reality ; then, and then only, have we any 
assurance as to its truth. 

This test of illusion is intellectually satisfactory This would 
only up to a certain point. For on closer examina- ^outside" 
tion we find that it is a test which none of us can our minds. 
use ; it is, as the Arabs say, a gift of almonds to the 
toothless. The outer reality would be a serviceable 
criterion of illusion if we could be at once within our 
minds and outside them, so as to compare our own 
mental pictures with the facts as they really are. 
But we cannot escape our own mental bounds. The 
idea we make of the external world is not obtained by 
some immediate and unerring intuition ; it is a labori- 
ous construction of ours out of our individual sense- 



112 



Experimental Psychology- 



perceptions. To get at the reality by which we are 
to determine the accuracy of our perceptions, we 
have to depend upon the very images and processes 
whose veracity is open to question. Out of our sen- 
sory images — a mixture of perceptions and illusions 
— we have to decide as best we can what the real 
world is. It would seem, then, that instead of being 
able to test illusions by our knowledge of reality, we 
must first be able to sift out the illusions themselves 
from our truthful perceptions before we can say with 
decision what the real world is. 



Experience 
involves a 
sophistic 
knot 



which we 
proceed to 
cut. 



Experience is 
used to check 
experience. 



For one who would be satisfied with no test which 
is not at once convenient and infallible, the case must 
be pronounced hopeless. Experience in this regard 
always reveals a curious instance of working in a 
circle : we cannot be certain what the real world is 
without distinguishing illusions from perceptions ; we 
cannot distinguish illusions from perceptions without 
first determining what the real world is. Here is a 
pretty tangle that would have rejoiced an ancient 
sophist. In practical life, however, we never stop 
to untie the knot; we cut it. We simply put our 
trust in the general run of experiences, and with them 
as standard we decide the worth of any particular 
case. Our practical test, consequently, is whether 
the special interpretation we have given our sensory 
impressions accords with the general system of our 
experience. If past experience is not sufficient to 
decide the case, I may immediately get additional 
experience to see whether it supports or condemns 
the interpretation I have made. If the tactile im- 



Illusions and their Significance 113 

pressions at my finger tips of the one hand sug- 
gest that two pencils are touching me, and yet the 
pencil as I grasp it with my other hand gives the 
clear impression of but a single object, I lose faith 
in the first interpretation ; and if sight, moreover, 
assures me that but a single pencil is there, I re- 
ject the early impression as illusory. But if, when 
any of us put a single pencil between our crossed 
fingers, the double tactual impression were confirmed 
by the great body of our experience — if we not only 
felt two pencils between the two crossed fingers, but 
also felt two with our other hand, receiving besides 
a visual impression of them both, and had hence- 
forth all the quiet satisfaction that comes from pos- 
sessing two, being able to use up, lend, or mislay 
one, and still have the other ; and if, moreover, our 
present experience accorded with our memories of 
past experiences, and was confirmed by the testimony 
and behavior of other persons, then we should all 
regard this as a valid perception and no illusion at illusions are 
all. Our only way of recognizing an illusion is by ^hfte^en- 
the fact that sooner or later it breaks with the body erai system 
of our perceptions ; one of our other senses, or the ° ie nce C ~ 
same sense under different conditions, does not con- 
firm it, or it is confirmed by all the senses for a while 
only. Dreams are illusions of an elaborate kind, and 
hold together marvellously. So long as all the parts 
do hold together, there is no knowing whether we 
are dreaming or awake. But after a while the bubble 
bursts ; the dream forms disappear as things in real 
life never do, an influx of law-abiding experiences 
occurs, fitting into the still larger system of memo- 



fails in the 
insane. 



114 Experimental Psychology 

ries and associations, and in comparison with these 
the dream group immediately seems fantastic and 
unreal. 

It is clear, therefore, that we do not go outside our 
minds to detect illusions ; we have no immediate view 
of reality by which we may decide their truth. The 
experiences themselves are employed to judge one 
another. For most of us there is a stable mass of 
perceptions which offers a good practical criterion in 
This test any questionable case. But there are unfortunates 
whose experience does not allow so ready a dis- 
crimination. In the insane, the figures of imagina- 
tion form such abiding and consistent groups, they 
occur in such orderly array, that, in time, the usual 
tests of reality fail. Their hallucinations show so 
many of the marks of reality, that the patient is 
finally at a loss to tell what is real and what is not. 
Or if he still have power to make this distinction, the 
effort of attention which this requires becomes too 
great, he gives up the struggle, and finally allows 
fact and fancy to mingle in wild confusion. 

The relation of any given item to our whole ex- 
perience, consequently, determines whether it is real. 
It is not sufficient that the experience have a basis in 
sensation, as is sometimes said. Our illusions usu- 
ally have in them sensations enough ; what they 
lack is harmony with the whole. They are discord- 
ant elements that refuse to clasp hands with the rest 
of our world, and so are adjudged unreal. 1 

And yet, in strictness, even our illusions are not 

1 As regards the view that the supreme test of reality is a social one, 
cf. p. 157- 



Illusions and their Significance 115 

unreal. Our dreams are real dreams ; hallucinations Seen aright, 
are real hallucinations. So that, even in these cases, harmon1ze° nS 
we are face to face with a fact of the world and not with the sys- 
with a nonentity. And for this reason, even our de- em " 
ceptions must in some way belong to that harmonious 
system of experience which I have tried to show is 
our final test of what is real. We may speak as if 
they were rejected because they would not accord 
with the system. This, however, we may now see is 
only a convenient half truth. If our illusions were 
not somehow in harmony with the whole, our scien- 
tific faith leads us to believe that they would never 
occur. The discord arises because we try to put 
them in the wrong part of the system. They have a 
proper place ; they belong among our personal and 
mental acts, and not in the physical world ; and 
rightly understood they harmonize beautifully with 
the general character of experience. For the psy- 
chologist, they fit perfectly into the mental system ; 
they are among its interesting realities. He scruti- 
nizes them, he measures and times them, and many 
he can explain. Pure unrealities, of course, could not 
be dealt with thus. 

A healthy mind will, consequently, find in illusion They do not 
no ground for discouragement. From time immemo- J^t of the 
rial, the errors of sense have been pointed to as a mind, 
proof of the unreliability of our powers. How can 
we be sure of anything, when our simplest faculties, 
our processes which come closest to external reality, 
are so deceptive ? But this is only one side of the 
case. There is also the other side, that we not only 
have illusions, but we know that we have them ; and 



n6 Experimental Psychology 

the power of detecting them ought to give us quite 
as much ground for congratulation and self-confidence 
as the illusions themselves do for distrust. If it were 
not for the general soundness of our life, we should 
never be aware that anything was amiss. So that no 
doctrine of total intellectual depravity can ever be 
supported by appeal to the deceptions of sense. 
They are rather an evidence that in the perceptual 
life, as elsewhere, there is a mingling of good and 
evil, of true and false. And since experience shows 
that along with the errors comes also the power of 
correction, knowledge is in the ascendant, and the 
future is secure. 
Develop- Shall we conclude, then, that a more perfect men- 

mentneed ^\ adjustment will free us from illusions? It might 

not free us J ° 

from them, seem from what was said earlier that such would 
be the case. If illusions spring from misinterpre- 
tation, — spring not from our sensations, but from 
the way we mentally supplement our sensations, — it 
would seem that when once we knew the truth the 
illusions would be dispelled. As a fact, however, 
many illusions will not down even when we know 

;■ a m m m m m " 

!■■■■■■■; 

Fig. 21. — Miinsterberg's figure (slightly modified). 



their character. Even after we know, for instance, 
that the contiguous edges of the squares in Miinster- 
berg's figure (Fig. 21) run parallel to the lines ab and 
cdy the appearance remains contrary to this knowl- 
edge. And we may measure with compasses and 



Illusions and their Significance 117 

convince ourselves that the lower of the concentric 
arcs above the horizontals in Fig. 22 is the contin- 
uation of the curve below the lines, and yet the 
upper persistently appears to have this character; 
and so with a host of other illusions. The fact that 



Fig. 22. — The lower of the arcs above the horizontal is the continuation 
of the curves a and b. (Verified by measuring from the centre c.) 

further knowledge does not destroy their sensible 
force demonstrates how complicated the mind is, 
and what inconsistencies it can harbor. Our modes 
of interconnecting and interpreting our sensations 
are due to deep-seated mental habits, lying beyond 
the immediate control of our will, and even to a large 
extent beyond the influence of logical evidence. 
They have become ingrained through the hard 
schooling of years and, possibly, of generations. 
The judgment from the evidence, however, — our 
knowledge of what the unperceived facts behind 
the illusions are, — lies on the surface, and does 
not penetrate into the deeper mental constitution. 
Illusion is consequently compatible with perfect illusion is 
knowledge ; and a higher mental plane would assure co ™P atl J le 
us only of the power to see through all deceptions, knowledge, 



1 1 8 Experimental Psychology 

but would be no guarantee that the illusions them- 
selves would disappear. They would simply lose 
their power to mislead us ; they would not be delu- 
sions, nor would they in any wise obscure our practi- 
cal and moral relations. As soon as we are able to 
see around or through an illusion, it is no longer a 
hindrance, no longer a handicap, and consequently 
the process of natural selection or of adaptation to 
the environment cannot be depended upon to eradi- 
cate it. In fact, we may go farther than to say*that 
illusions will continue because there is no especial 
need of our ridding ourselves of them, or that they 
will remain by inertia, for want of an opposing 
and may force. There is a positive utility of a higher kind 
lvalue 551 " * n certani illusions. Judged by the standards of 
biology, they are defects ; they are signs of an im- 
perfect adaptation of the mind to its environment. 
But this is only half the truth. They are deficiencies 
that leave us the richer. For, having discovered that 
they exist, mankind makes them of service in that 
half-practical world of play and art. How much of 
the fascination of picture and of drama depends upon 
the light veil of illusion that floats over the whole, 
so fine that we at once see it and see through it. 
We have here the curious pleasure of being deceived 
and yet a party to the fraud. If the deception were 
perfect, it would be mere trickery ; and yet, too, if 
there were no deception, we should lose some subtle 
charm. If illusions, then, are to be described in pro- 
saic scientific terms as cases of defective adaptation, 
may the defect in some faint form continue in this 
life and in the world to come ! 



Illusions and their Significance 119 

In concluding, let us recall the main teaching of The main 
illusions in regard to the character of the mind, ^j^f ° 
They show the interplay of the different sides of 
consciousness. Attention influences judgment, and 
expectation affects sensation. There are no sharp 
borders here. The usual divisions we make in psy- 
chology are not divisions in the facts themselves; 
there are no functions which act in isolation and 
without mutual dependence. Illusions, then, bring 
home to us the organic unity of the mind; they make Mentally, ail 
it evident that the various sides are in constant sym- things con " 

J spire. 

pathy and interaction, and that to some extent each 
participates in all that is done. 

But the more specific teaching is as to the manner Refutation 
in which experience is constructed. Illusions, when ^doc-*^ 
understood, are the most striking refutation of the trine, 
common belief that experience is a kind of direct im- 
press of external nature, we being passive recipients 
of the facts as the world imprints them upon our 
senses. There is a passage in the Thecetetus which 
sounds odd enough to our modern ears, but which 
seems to be a foreshadowing of the truth. From the 
outer object, Plato tells us, 1 there comes an image 
toward the eye ; and out from the eye there flows 
sight to meet the object. The union of these two 
somehow produces our actual perception of the thing. 
Curious as we may account this early psychology, it 
expresses the truth that experience arises by a union 
of two different factors — something which comes 
from the outer world, and something which we our- 
selves contribute from our inner store. The outer 

1 Thecetetus, Steph., 156. 



120 Experimental Psychology 

impression alone, according to Plato, is not enough ; 
we must do our part; we must meet the impressions 
halfway. The outgoing sight darting from the eye 
to meet the image coming from the object, seems to 
represent what we now call our subjective elaboration 
of the incoming impressions — represents the associa- 
tions or suggestions which these impressions arouse, 
— the form or arrangement into which we force them, 
and without which the bare sensations would have no 
meaning whatever. 
Experience So long as our contribution to the experience — 

implies in- ^ assoc i a tions, the suggestions, the "form" — is in 

cessant activ- ' °° 

ityonour perfect keeping with the outer facts, we might well 
part ' believe that external nature itself was the sole and 

efficient cause of our panorama of the world, that 
we had really received the experience bodily from 
the objects themselves. But the frequency of decep- 
tive experiences, of perceptions contrary to fact, makes 
us see that this cannot be ; that we ourselves are all 
the while a chief source of experience. Deprived of 
the outer world, we should indeed be without the crude 
materials of experience ; but the finished product, the 
real vision of nature and of history, depends quite as 
much upon us. The world, then, is beheld by us only 
indirectly, as we reconstruct it out of our sensations. 
Like the Lady of Shalott, each of us views the gay 
pageant of life as in a glass, and even this reflected 
image comes to us only as we keep to our task. Once 
we cease our activity, once we stop our weaving, at 
that instant — as in the poem — the glass breaks, the 
vision vanishes, and around us lies but the tangled 
web of meaningless impressions. The chief psycho- 



Illusions and their Significance 121 

logical significance of illusions, then, is to bring out 
the fact that the mind, even in what appears its most 
passive moments, is in ceaseless activity, and that 
its various powers of intellect and feeling and will 
constantly interplay. These illusions thus force us 
to the paradox that our very deceptions are an im- 
portant instrument of knowledge. 



CHAPTER VII 

EXPERIMENTS ON MENTAL SPACE, PARTICULARLY 
THE SPACE OF THE BLIND 



Kant and the 
psychology 
of space. 



Interest 
aroused by 
modern 
geometry. 



The various questions connected with our percep- 
tion of space were given by Kant a dignity that they 
had not before possessed. Locke and Berkeley had 
already made the subject inviting, but Kant brought 
it to the front as one of the crucial problems in re- 
gard to mind. Our view on this subject, he showed, 
would to a large extent indicate what our belief as to 
the validity and range of human knowledge in gen- 
eral should be. Under the influence of Kant's doc- 
trine that our perception of space is somehow on a 
different mental level from our perception of light or 
of sound, and that it indicates the possession of mental 
powers transcending the impressions of the moment, 
the psychology of space became a thing of flesh and 
blood, and has ever since remained so. Against Kant 
are the British ranks from Hume to Spencer, main- 
taining that there is nothing anomalous here, noth- 
ing that points to peculiar or transcendent powers ; it 
is all a matter of sensations and their association. 

The interest which the psychology of space has 
derived from these contentions has been recently 
stimulated from an unexpected quarter. The dis- 
pute as to the character of our space-experience has 
broken out in mathematics. Many now believe that 

122 



Experiments on Mental Space 123 

what had been so long accepted as demonstrable 
in regard to space — for example, that the interior 
angles of a plane triangle are equal to two right 
angles — is, after all, but characteristic of the partic- 
ular space with which we are familiar, and that there 
is at least the possibility of other kinds of space 
whose properties would not accord with the principles 
of the older mathematics. Out of such speculations 
has developed the modern non-Euclidean geometry. 

The work of the laboratory, and of the experi- 
menters outside the laboratory, — of the surgeons, 
for instance, who have contributed so much to our 
knowledge here, — is in sight of these interesting 
questions ; but they must remain in the background 
until the details of the experimental studies have 
been brought more clearly before us. 

We all have an instinctive feeling that our mind The marvel 
reaches out into our very skin, and is in the actual °£ t ?^ ™ d s 
presence of the objects that touch us. Sight also 
seems to bring us face to face with the world, as if 
we looked out at it directly through the pupil of 
the eye. But the more prosaic, and yet, after all, 
more wonderful fact is that the mind receives only 
indirect reports of what is going on without. The 
cortex of the brain, with which our consciousness 
is connected, lies in darkness, deep in its coatings of 
tough membrane and skull and flesh, and connected 
with the outer world only through the medium of 
long and delicate fibres that bring in messages from 
the outposts of sense. It is as if a person were 
secluded in an inner chamber and learned of the out- 



I2 4 



Experimental Psychology 



The limit of 
its power 



side world only by an inconceivably elaborate system 
of wires and signals. From some difference in the 
signals accompanying the different messages, or from 
some peculiarity either of the tone or of the intercon- 
nection of the messages themselves, we are able to pic- 
ture the scene which is causing the influx of sensations. 
The mind must distinguish the various impressions 
from different parts of the skin, or from the innumer- 
able points on the surface of the eye, and refer each 
to its proper place in the external world. When one 
considers the complexity of the task, — that we can 
accurately tell not only the direction but also the 
ever changing distance from which sensations come 
through the rods and cones of the eyes, — the ease 
and security with which this amazing performance is 
accomplished is one of the marvels of life. 

Experiment shows, however, that there is a limit 
even to this power. When impressions come from 
points too close together we are at last unable to 
keep them apart. In the case of sight this limit is 
very low : fine lines, side by side, become con- 
fused and indistinguishable when the distance 
between them makes an angle in vision of less 
than about 6o n . Stars in the heavens cannot 
be seen as separate when they are closer 
together than 30". Under more favorable 
conditions, however, we can distinguish posi- 
tions that are as close together as 7" of arc, 
or about -g-J-g- of a degree. When, for instance, 
two lines are placed end to end, and one of them is 
shifted slightly to one side, as in the diagram (Fig. 23), 
while still remaining parallel with the other, a dis- 



Fig. 23. 



Experiments on Mental Space 125 

placement of J of an inch can be detected at a dis- 
tance of about 400 feet. 1 This means that in the 
minute image at the back of the eye, differences of 
locality amounting to but -5- o~0 -qo °f an lncn stl ^ § lve 
distinguishable impressions ! Touch, while not so 
delicate as this, is also capable of exceedingly fine 
perceptions. An elevation of but ^ qVo °^ an inc ^ 
above a smooth surface is noticed by rubbing the 
finger tips over it. 2 But in experiments where we 
have to tell whether we are being touched by one or 
by two points, even at the finger tips we can scarcely 
distinguish impressions that are ^$ of an inch apart ; 
and on our backs we often confuse sensations that 
are separated as much as two inches. 

Our first thought might be that the limit in all seems not to 
these cases is fixed by anatomical conditions ; that 5f fixed by 

J ' the sense- 

the different impressions when they come too close organs, 
together run on to the same sensory terminals, and 
thus become confused. But the minimum is more 
variable and often much smaller than it would be if 
due to a limit in the supply of nerve endings. In the 
case of touch, a few days' practice in feeling compass- 
points will reduce the threshold to a small fraction of 
what it was ; and reduce it not alone at the part of 
the skin where the practice has been given, but at 
other parts as well. We can hardly believe that the 

1 Cf. "A New Determination of the Minimum Visibile," etc., in 
the Psychological Review for September, 1900 (Vol. VII, p. 429), and 
also in the Compte Rendu des Seances, IV e Congres International de 
Psychologies Paris, 1901, p. 411. Cf. Bourdon, " L'acuite stereo- 
scopique," Revue Philosophique, January, 1900. 

2 Brown, " Notes on a New Form of vEsthesiometer," Journal of 
Physiology, Vol. 27, p. 85. 



126 



Experimental Psychology 



How this is 
possible. 



Simile of a 

signal 

system. 



supply of nerves is correspondingly altered at such 
short notice. And in vision our discrimination seems 
about four times as fine as it ought to be, if the merely 
anatomical measurements of the rods and cones in the 
eye determined its limit. 1 

Any full explanation of this curious phenomenon 
would take one far into technicalities ; but perhaps 
some assistance in clearing up the paradox that local- 
ization is finer than nerve differences may be had 
from keeping in mind that even the finest impressions 
never come from a single isolated nerve terminal in 
the eye, and probably do not in the skin. This is 
shown in vision by the well-known phenomena of 
irradiation and of contrast, which prove that even the 
smallest ray of light stimulates not alone the part of 
the eye on which it directly falls, but also the neigh- 
boring regions, as by some subtle sympathy between 
the different parts of the retina. The nervous ele- 
ments thus respond always in groups and never sin- 
gly. So that the space-signal by which the place of 
origin of a sensation is designated is not some simple 
sign comparable to the single numeral which drops 
down in our electric signal boxes when the bell rings, 
but must be a number of simultaneous signals, where 
the peculiar grouping tells much more than any one 
of them could tell alone. Imagine an electric signal- 
box where the room in the house from which each 
signal came was denoted not by a single falling nu- 
meral, but by the simultaneous flashing of a great 
number of lights in the box, and this was moreover so 
delicately constructed that each light passed through 

1 See the "New Determination," etc., cited just before. 



Experiments on Mental Space 127 

various gradations of intensity, or changed its color 
according as the person giving the signal was nearer 
or farther from the button that controlled the signal. 
In that case any one would have sufficient data to 
know not only the room from which the signal issued, 
but could, according to his training and mother-wit, 
determine up to any degree of exactness the particu- 
lar spot in the room where the person who gave the 
signal stood. The limit of the number of wires in 
the house and the distance apart of their terminals 
would in this case not limit the exactness of the 
localization of the summons. The local signs with us The mental 
seem, from the experimental evidence, to be of this ^auty. 
complicated order — endless changes and rearrange- 
ments in the impressions coming from joints and 
tendons and muscles and skin and retina. The con- 
scious discrimination of place, therefore, is a high 
order of mental achievement — not mere rote-work 
nor rule-of-thumb action, by any means. No two 
places, however close together, can give exactly the 
same combination of sensations ; there will inevitably 
be some difference in their relative intensities or qual- 
ities. But there is a limit to our power of following 
these infinite gradations and combinations, and in 
this, rather than in the distance apart of the nerve 
terminals in the eye or in the skin, must we look for 
the causes that determine the spatial threshold. 

Thus far it has been tacitly assumed that our which is the 
acquaintance with space comes through both touch s ^f x * ense 
and sight independently.. But psychologists are di- ceiience? 
vided into parties on this very question. First, there 



128 Experimental Psychology- 

are the tactualists, as we might call them, who be- 
lieve that touch (including our muscular impressions) 
is the spatial sense par excellence, and that sight alone 
cannot acquaint us with the size or shape or distance 
or direction of things. On the other hand, there are 
the visualists, who maintain that sight is the only 
sense that gives us a knowledge of these things ; 
that touch is a mere time-sense and gives us no feel- 
ing of space whatever. And finally, there are some 
who hold that touch and sight perform this work in 
common; that each of them is capable of space-per- 
ception, and that we consequently cannot attribute 
this to either of the senses as its peculiar and exclu- 
sive function. 
The parti- The question is an old one. The classic query of 

Molyneux to Locke as to whether a man born blind 
who had become familiar with a cube and sphere by 
touch could, if suddenly given sight, correctly dis- 
tinguish and name each of these by vision alone, 
shows the problem in its early form. For if touch 
and sight had space as their common feature, we 
should expect that a person who had become ac- 
quainted with a form by one of these senses would 
immediately recognize it when this same form ap- 
peared to the other sense. Locke believed that such 
a recognition would not be possible ; and Berkeley's 
"New Theory of Vision," going much more thoroughly 
into the underlying psychology of the question, ar- 
rives at a conclusion 1 quite in agreement with Locke. 
Berkeley was, in fact, the first to develop systemati- 
cally the notion that vision, in its primitive purity, 

1 See p. 5. 



sans of touch. 



Experiments on Mental Space 129 

lacks all space-character, and that it gets this only 
indirectly by association with tactile impressions. By 
long association, he believed, sight comes to suggest 
tactual experiences which are spatial, and consequently 
comes to suggest space, although the visual experi- 
ences themselves are spaceless ; just as the odor of 
brass might suggest weight and resistance without 
the olfactory sensations themselves having weight 
and resistance. 

The most striking evidence on this question comes Experiments 
from experiments on persons born blind, and given after ^opera- 
relief comparatively late in life by surgical aid. In congenital 
a number of such cases, after the patient had to cataract * 
some extent recovered from the operation, he was 
allowed to look at objects already familiar by feeling, 
and was asked to name them. From Cheselden's fa- 
mous case down, the testimony is fairly uniform that 
the patient cannot recognize objects by sight alone. Usually, 
He must first touch the thing or he fails to identify fa ™ iliarob - 

J jects are un- 

it. But once he has learned how the felt thing looks, recognized 

thereafter the sight of it suffices for its recognition. byslg t# 
Cheselden's patient, on seeing a familiar cat, could 
not tell what it was. Home's patient thought that 
a number of square and oblong cards were round ; 
while Raehlmann's patient, when shown a large bottle, 
said it might be a horse. And when one of the sur- 
geons twitted him on not knowing the difference be- 
tween the two, he replied sheepishly that it was not 
so easy after all. 1 The young gentleman operated on 

1 For the more detailed references and a discussion of these cases 
and of those cited below, cf. "The Spatial Harmony of Touch and 
Sight," Mind, October, 1899. 
K 



130 Experimental Psychology 

by Franz, however, was the most intelligent and best 
educated of them all ; and he was able, by very close 
attention, to distinguish a square, a circle, and a tri- 
angle ; but he afterward confessed that the character 
of the figures did not become clear to him until he 
seemed to feel them with his finger tips. Then, al- 
though he was not actually touching them, he recog- 
nized the forms immediately. And again, in pointing 
out which of two lines was horizontal and which was 
vertical, he first carried his finger cautiously to the 
wrong one, and then corrected himself. Trinchinetti's 
little boy and girl grasped at things as if they ex- 
pected to find them in the neighborhood of their eyes. 
So, too, Dufour's patient, when asked to take hold of 
a door-knob which he seemed to see, groped around 
for it like one in the dark. Rarely in these persons 
does sight seem to have been, at first, of much assist- 
ance in guiding their movements ; in fact, one of the 
patients, even weeks after the operation, could hardly 
be induced to take a practical interest in what his eyes 
revealed. He would neglect the reports of sight, and 
fall back persistently into his old world of tactile clews. 
The results Such observations are made much of as evidence 

seem to favor ^at sight in its virgin state gives us no idea of space 
ists 1 view. whatever. For, if the things of sight were really 
spatial, it is argued, why did these patients find the 
visual world such an unfamiliar land ? Even though 
the sense-materials were entirely novel, the old forms , 
it would seem, ought to be recognizable if there were 
actually a common element of space in the two kinds 
of experience. Do not the experiments, therefore, 
show that Berkeley was right, and that until associa- 




Fig. 24. — A negative of Fig. 25, 



Experiments on Mental Space 131 

tions have had time to develop, touch and sight have 
absolutely nothing in common ? 

It does not seem to me that they mean this. To Possibility of 
show that they can well be interpreted in another way ^fg^fta- 
will require a somewhat long discussion ; but the sub- tion. 
ject is so interesting and so important that a careful 
weighing of the evidence may not seem out of place. 
The evidence against there being any underlying simi- 
larity between touch and sight is, as has been seen, 
based largely upon the failure to recognize by sight 
objects known by touch. 

But in the first place it must be remembered that a Difficulties of 
person is at a great disadvantage immediately after a surgical ei 
surgical operation on his eyes. There are often pain operation, 
and tears, and at best the eyes are not well under 
control. A lack of proper accommodation and co- 
operation of the two eyes must make the impressions 
which they give far from clear. But if, for this reason, 
one sees men as trees walking, his experience is never- 
theless quite as spatial as if he sees them as men. The 
difficulty may be largely in telling where one thing 
leaves off and another begins ; so that object and sur- 
roundings and background are poorly discriminated. 
Mere vagueness of impression is doubtless partly the 
cause of the defective recognition. But vagueness of 
objects is by no means equivalent to absence of ex- 
tension. In gloom or mist we often fail to identify 
things, and yet they are certainly spatial. 

But even disregarding this, the fact is that in our Recognition 
usual recognition of things we depend comparatively ^ ep c e h n J s e ° n 
little on their pure space-form. Take so simple an sides spatial 
instance as that of the tin cup which Johann Ruben, form ' 



132 



Experimental Psychology- 



Reasons for 

overlooking 
mere shape. 



Recognition 
may be 
hindered 
even when 
the form is 
unchanged. 



in Raehlmann's account, could not tell by sight. 
Many would perhaps say that we appreciate that 
such an object is a cup by the shape of the thing, 
and that nothing else about it is of great importance. 
But imagine yourself searching for a tin cup in the 
dark and suddenly laying your hand on something 
the shape of a cup but made of ice or butter; the 
chances are that none of us would take it for a cup 
at all. What we should mark would be the damp, 
slippery feeling of the thing, and these would be so 
prominent that the form would pass unnoticed. 

Now it could quite as well be urged that touch here 
gave us no sense of form because we might not dis- 
cern the shape of the icy or buttery thing, as that the 
newly attained sight gives no sense of shape because 
these patients fail to recognize objects by their shape. 
In their case the visual sense-filling of the object 
is infinitely novel and unexpected, infinitely removed 
from the familiar temperature and hardness and re- 
sistance in which the shapes of things had hitherto 
been embodied. The color, the glitter, the shad- 
ows around and upon each object, are something for 
which touch offers no counterpart whatever. And 
these unexpected properties are so absorbing, so baf- 
fling, that the abstract space-quality, the bare geo- 
metric character of the thing, fails to come to the 
front. The other aspects crowd forward and leave 
no interest for these more hidden marks. 

The fact that recognition may be seriously inter- 
rupted even when the space-relations of objects are 
undisturbed may be brought out in other ways. 
What an unfamiliar look there is, to the unpractised 




Fig. 25. 



Experiments on Mental Space 133 

eye, in the photographic negative of even a well- 
known picture (Fig. 24). How many things in it 
escape us that are noticed instantly when light and 
shade are given their accustomed value (Fig. 25). 
Here the abstract space-relations are certainly left 
intact; the form, the outlines, are the same in the 
negative as in the positive, but the mere variation of 
the chiaroscuro hinders us in singling them out, and, 
for that reason alone, many of the details of the 
picture are as good as lost. Or if instead of chang- 
ing the light and shade we merely invert a familiar 
scene, the recognition of forms is again perceptibly 
hindered (Fig. 26). If recognition flowed from the 
abstract geometrical character of the experience, it 
ought to occur as well after inversion as before. The 
inversion does not affect the shape or the interrelation 
of things in the scene, and yet the details are for some 
reason much less readily disengaged and identified. 
If, moreover, not merely a part of the visual experi- 
ence, as in this case, but all things about one were in- 
verted, it is remarkable how many things in plain view 
would be overlooked. Under these circumstances 
one may not know his next-door neighbor, and his 
home village may seem as strange as a foreign land. 
These examples have been multiplied to show that 
our recognition of objects depends upon many factors, 
and that the objects may appear strange to us even 
when their abstract form is all the while what we How much 
have been accustomed to. The mere resetting of the more> when 

we pass to an 

old form makes it unknown. 1 And yet the resetting absolutely 

new sense ! 
1 An interesting case from a totally different realm, where recogni- 
tion would at first sight appear to be aided by novelty of setting, occurs 



134 



Experimental Psychology 



The argu- 
ment that 
sight origi- 
nally is non- 
spatial thus 
falls. 



Evidence 
from Franz's 
case. 



in the illustrations just given is as nothing compared 
with the reappearance of tactual shapes in visual 
materials never before experienced. The sifting out 
of the common elements in two kinds of experience 
so closely akin as upright and inverted vision, or as a 
positive and negative arrangement of light and shade, 
must be the merest child's play in comparison with 
the perplexities of one just attaining sight. The very 
difficulty in analyzing the new experience, in select- 
ing points of attack, and in discerning what is sig- 
nificant and what is not, in the endless confusion of 
light and shade and color — this would certainly 
account for the failure of those surgically operated 
upon to recognize familiar objects by sight alone. 
The main argument for the non-spatial character of 
vision thus falls to the ground. For the failure to 
recognize familiar things by the newly attained vision, 
which is the main evidence adduced, can well be 
explained in other ways. 

And this conclusion that sight is a space-sense is 
supported by the results of Franz's experiments 
already referred to. The case he reports makes it 
clear that if the patient is clever enough ; if he has 
the requisite intelligence and training, he can recog- 
nize, albeit with difficulty, simple forms like a tri- 



in the Indians' recognition of music. I once heard the late Professor 
Fillmore say that while among the Omahas he found that only when 
he introduced the harmonic "parts" did they recognize their songs 
when played on the piano. They failed to recognize them when 
played as simple melodies, although they themselves did not sing in 
parts, but in unison. But may it not be that the instrumental harmo- 
nies, in some subtle way, better imitated the chorus, and for this reason 
helped the recognition? 




Fig. 26. 



Experiments on Mental Space 135 

angle, a square, or a circle, even at first sight. His 
patient's remark that these figures were not identified 
until he noticed how they would feel in his finger- 
tips, is no evidence that the object as perceived by 
sight is from the beginning unlike its tactual counter- 
part. For, if the two experiences were not alike, 
how could the sight of the figure have suggested to 
his finger tips how it would feel before he had actu- 
ally touched it ? The suggestion here seems to have 
been clearly based on an underlying similarity in the 
impressions. 

But even when we have reached the conclusion But which 
that sight gives us spatial impressions, the old prob- f^^™ * 
lem is still present, although on a reduced scale. 
For vision itself is a compound sense. It gives us an 
intimate mingling of two very different kinds of sensa- 
tions : the one kind being pure impressions of light and 
color, arising from the action of the nervous coating at 
the back of the eye, the retina ; while the other kind 
are sensations of touch and strain, coming from the 
various muscles both within and without the eye-ball, 
and from the tactile surfaces of the ball, socket, and 
lids. It would, indeed, be difficult to show that impres- 
sions of light and color alone, without the aid of these 
tactile and motor accompaniments of vision, would 
have spatial form in their own right. With regard to 
this, no crucial experiment has ever been made. 

On the other hand there is plenty of evidence that importance 
in our fully developed vision these motor accompani- of the tactlle * 

J x L muscular 

ments play a very important role. A partial paraly- element in 
sis of certain muscles of the eyes makes one incapable vlslon - 



136 



Experimental Psychology 



Shown by 
the " pseudo- 
scope " 



and the 

"telestereo- 

scope." 



of judging correctly the position of things ; the diffi- 
culty of moving the eyes to one side, for instance, 
makes objects seem to lie much farther on that side 
than they really are. Not only this sense of the direc- 
tion of objects, but also our feeling of their distance 
from us is largely due to the feeling of movement and 
strain in the eyes, and not simply to sensations of 
light and color. In regard to distance this is well 
demonstrated by the pseudoscope, an instrument con- 
trived to reverse these motor sensations just spoken 
of, by practically transposing the eyes, so that the 
right eye acts as if it lay to the left of the left eye. 
In looking at things through this instrument (one of 
whose forms, 1 made with two mirrors, is shown in 
diagram in Fig. 27) the eyes have to converge more 
for farther objects and less for nearer ones — just 

the reverse of our normal 
eye movements ; and as a 
result the perspective of 
the scene is, under favor- 
able conditions, turned in- 
side out. Far becomes 
near, convex becomes con- 
cave, and instead of an object concealing what is 
behind it, it cuts its own outline out of objects that 
seem nearer the observer, and is seen through them. 
A slight change of this instrument gives what is 
called a " telestereoscope," which has an effect as if 
the eyes were suddenly placed abnormally far apart 

1 Cf. " A Mirror Pseudoscope and the Limit of Visible Depth," 
Psychological Review, Vol. V, p. 632, and also in the Scientific Ameri 
can, Dec. 10, 1898. 



\ 



o o 

Fig. 27. — Pseudoscope 
(one form). 



Experiments on Mental Space 137 




3C 



o 

c b a 

FIG. 28. — Telestereoscope 
(one form). 



— carries them, as it were, to a and c in Fig. 28, in 
contrast with their real position at a and b. It thus 
intensifies the eye movements as we look at different 
portions of the scene, and as a result strangely 
increases the usual depth 
effect. The perspective ap- 
pears pulled out, accordion- 
like, to surprising lengths. 
These experiments show 
that the relief which ob- 
jects have in the fore- 
ground of vision — the 
vivid plastic effect which the familiar stereoscope so 
well reproduces — is utterly wanting to beings whose 
vision has mingled with it no sensations of muscular 
movement and friction coming from the cooperation 
of the two eyes. Many fish and birds, consequently, 
while having two eyes, but without any overlapping 
and conflict of the fields of view of the two eyes, 
must lack this plastic element in their visual experi- 
ence. Such vision can give only indirect suggestions 
of distance like that offered in a skilful painting, 
but never our unique impression of binocular depth. 
To this extent, therefore, we must acknowledge 
that visual space is dependent on touch and muscular The retina is 
movement. But granting that our most vivid and a s P ac ^ _ 

b => organ in its 

accurate perception of distance and of direction is own right, 
due to sensations which are not purely of light or 
color, we need not go to the extreme of maintaining 
that distance and direction cannot be given by light 
and color at all. The inner nervous coating of the 
eye — the retina — seems to resemble the skin in its 



138 Experimental Psychology- 

power to give a vague feeling of outwardness and of 
place, without the aid of the other senses. When a 
Effect of dis- surgeon transplants a portion of the skin, for some 
tionsTofFt?^ time a ^ ter the operation things touching this trans- 
planted surface seem to be in contact with the body 
in the region where this portion or skin used to be. 
The similarity of the space-function of the retina is 
suggested by the occurrence of a like phenomenon 
in vision. Wundt has related that a disease of the 
underlying tissues in one of his eyes caused portions 
of the retina to shift their place. The scene itself 
seemed to suffer distortion in consequence. Objects 
were localized as if they were stimulating the place 
in the eye to which these nervous elements had 
hitherto belonged, and all things were seen awry, 
until the dislocated parts came finally to act as if 
they had always belonged in their new positions. 1 
As regards the importance of movement, then, the 
retina seems to be like the palm of the hand. Just 
as the hand, even when merely resting upon an ob- 
ject, obtains a vague sense of the relative direction of 
its different parts, and yet its movement brings out 
their positions more definitely and permits us more 
accurately to interconnect them and to cover a larger 
area; so with the eye. Its mobility gives a nicety 
and range of space-perception that a motionless retina 
could never attain. But the movements only intensify 
and perfect what would be there in some degree with- 
out them. 

Much more briefly must we consider the evidence 

1 Wundt, " Zur Theorie der raumlichen Gesichtswahrnehmungen," 
Philosophische Studien, Vol. XIV, p. 1. 



Experiments on Mental Space 139 

for what I have called the visualists' position. The The visual- 
supporters of this view would agree with all that has ^^J^ 1 
just been said as to the power of sight to make us exclusive 
acquainted with space at first hand, but would main- s P ace ~ sense - 
tain that it is the only sense that has this power. 
Touch and movement, they hold, can of themselves 
give no feeling of space ; those who have never seen, 
who have been born blind, live in a world that is for 
them, devoid of extension, — a pure time-world. This Accordingly, 
doctrine in fact gains its adherents chiefly among ^etho^ht 
persons particularly interested in the life of the blind, to live in a 
Platner, for instance, in the eighteenth century wo^d 1 ™ 6 " 
adopted this strange view; and within recent years 
Dunan reports that a number of French officials in 
charge of institutions for the blind are convinced that 
one who has never seen has absolutely no sense of 
space. 1 Platner has been quoted as if his testimony 
were well-nigh decisive. But he had, in truth, no 
very exceptional opportunities for studying the prob- 
lem, and offers practically no evidence whatever. 
He does little more than to assert somewhat impres- 
sively that for three weeks he investigated the case 
of a blind man and convinced himself that the blind 
know nothing of space. Dunan, on the other hand, 
does offer evidence, but it is evidence which after all 
does not make for his conclusion. He shows, for in- 
stance, that a blind man does not think of a distant 
object in the same way that a normal person does; 
that the perspective element must of necessity be 

1 Platner, Philosophische Aphorismen, ed. 1 793-1800, Vol. I, pp. 440 
et seq. ; Dunan, " L'espace visuel et l'espace tactile, Observations sur 
des aveugles," Revue Philosophique, Vol. XXV, pp. 357 et seq. 



140 Experimental Psychology 

wanting, for this is a matter entirely of sight. What 
we so prominently associate with distance, — the 
diminishing size, the converging lines, the loss of 
detail, the change of color, — all this must be absent 
from the blind man's picture of what is remote. But 
even so, we cannot conclude with Dunan that this 
implies that such a person has no idea whatever of 
distance. The essential thing is not that their rep- 
resentation should be identical with ours and should 
have exactly the same associations, but that there 
should be any appreciation of distance at all. With 
us, certainly, this appreciation is not inseparably 
bound up with the perspective of lines and of at- 
mosphere. Our most vivid impression of the third 
dimension is, in fact, independent of these. The 
striking relief in which objects stand that are within 
six hundred yards of us has nothing to do inherently 
with the factors upon which Dunan lays such stress. 
Within a certain distance of us, as the experiment 
with the pseudoscope just recounted shows, an object 
may seem nearer than another, in defiance of con- 
trary suggestions of size or of linear or aerial per- 
spective. Therefore these latter are clearly not the 
essence of our feeling of distance. 
Rejection of There is no evidence whatever that the blind do 
Dunan^iew not °htain something of this same plastic sense of 
the world through movements of the body and espe- 
cially of their hands and arms, although the range 
within which they have it must certainly be less 
than vision gives to us. If, on the other hand, we 
were to accept Platner's belief as correct, that the 
world of those born blind is a spaceless world, it 



Experiments on Mental Space 141 

would be difficult indeed to explain the instances 
where those surgically cured of blindness have been 
able to recognize simple forms by sight alone ; and 
equally difficult to explain the rapid progress even 
the others make in familiarizing themselves with 
space. Distance and direction and size do not appear 
to be absolute novelties to these abnormal persons. 
Their real difficulty seems to be merely to interpret 
the distances and sizes and directions of their new 
experience in terms of their older, tactual life. 

We may conclude, then, it seems to me, that touch Touch and 
is a spatial sense in its own right. The visualists, J lg a h t |^ re each 
like the tactualists, have a one-sided doctrine. For 
there is no single exclusive channel of this experi- 
ence, but both sight and touch give us a first-hand 
acquaintance with the world of extension. 



CHAPTER VIII 

THE HARMONIES AND DISCORDS OF SPACE PER- 
CEPTION, AND ITS PLACE IN EXPERIENCE 

with their We are thus brought to the view that the world of 

manyincon- extended things comes in upon us through at least 

gruities, how . i i -n i • 1 

do touch and two distinct channels. 1 But this conclusion, conso- 
sightever nant as j t seems w ith common sense, brings a fresh 

harmonize? ,.„,.. „ , , . 

difficulty in its tram. For we have now to explain 
how sight and touch, which are fundamentally so un- 
like, can nevertheless make us feel that they are tell- 
ing the self-same story. When we compare the 
conditions under which each operates, there seems to 
be nothing but a series of contrasts between them ; 
and yet the results are somehow harmonious. When 
I hold a ball in my hand it touches and excites a large 
surface of the palm ; but when I look at it, it stimu- 
lates a portion of the sensitive surface of the eye no 
larger than a pin's head. And yet the ball I see 
seems quite as large as the one I feel. Moreover, as 
I touch the object, it affects my hand ; but as I look at 
it, it influences a portion of the body removed from 
my hand, namely the eye. And yet, in both instances, 
the object seems to us to be in the same place. As a 

1 That hearing is also an independent spatial sense (though much 
more limited in many respects) seems highly probable. Cf. Pierce, 
Studies in Visual and Auditory Space Perception, New York, 1 901, 
pp. 180 et sea. 

142 



Spatial Harmonies and Discords 143 

final contrast, the image in the eye lies in a reversed 
direction from that of the impression on the hand; 
and yet we see the object as lying in the same direc- 
tion that it has for touch. In spite of all these incon- 
gruities in the tactual and the visual impression, the 
two senses work in perfect harmony and show us the 
same world. How is this to be accounted for ? 

It is sometimes said that there really is no problem it is no an- 
here; that there is no need of showing how harmony ^aYweare 
can result from such antitheses, because we are never never con- 
conscious of the minute image in the "fund" of the retinal im-* 
eye. It is true that the retinal impression is not felt age. 
in the eye, and yet this hardly seems to me to explain 
anything, but rather is part of the very fact that needs 
to be explained. Why is it, we may ask, that in sight 1. why is the 
we do not locate objects at the place where the sense- vl r ^e C ted' eCt 
impression occurs, while in touch we do ? Why while the 
this striking difference in our mental action in the tactua lsnot 
two cases ? It is certainly not because there is some 
native predisposition in the organs themselves to lo- 
cate their objects in this different way. We do not 
do it instinctively. On the contrary, it is due to ex- 
perience and associations. We learn that the things 
which give us touch sensations are at the skin ; and 
likewise we learn that objects which give us impres- 
sions of light and color are not at our eyes. When Causes for 
a child grasps a ball, he can pass his other hand at " n ot JJJJjJjJJ*" 
once over both hand and ball. This independent ob- impressions, 
servation shows that the object and the sensory sur- 
face lie in contact, and that it is not a case of action 
from a distance. The lips also feel hand and ball 
close together. And finally the eyes can observe 



144 Experimental Psychology 

them both in the same glance. From repeated ex- 
periences of this sort it becomes a fixed habit to feel 
the object that excites the skin as lying against the 
skin itself, 
why visual But where, now, shall the child locate the object 

aTe^oTfekln that he sees ? As ty^S a g ainst th e retina of the 
the eye. eye ? If the rest of experience supported such an 

interpretation, yes. But the fact is that the rest of 
experience suggests quite the contrary. In the first 
place, as the child passes his other hand over the 
hand grasping the ball, he does not come upon his 
eye lying against them both. His hand must make 
quite a journey after touching hand and ball before 
it touches the observing eye. Moreover, things that 
we know are hard and heavy do not impede the 
movements of the eyes when we look at them, while 
the same objects do check our movement more 
or less when we touch them. And so on ad 
infinitum. There are experiences enough and to 
spare to account for our reference of the objects 
away from the surface in the one case and to the 
surface in the other. There is no need of assuming 
that in vision there is an innate tendency to project 
the object. Nor, on the other hand, do we begin 
with a feeling that things are against our eyes, and 
later learn to project them. 
Objection Several of those successfully operated on for con- 

front cases of g en i ta i cataract — Cheselden's and one of Home's 

Cheselden & 

et ai. patients, for example — did, it is true, declare that 

things seemed to touch their eyes. But this means 
no more, it seems to me, than would our own feeling 
on passing from a dark room into very dazzling sun- 



Spatial Harmonies and Discords 145 

light ; something then often seems to " touch " our 
eyes, so strong is the accompanying feeling of dis- 
comfort and muscular contraction. For we must 
remember that just after an operation sight is usually 
coupled with pain and tears and muscular spasms ; 
and since these are naturally, from previous experi- 
ence, felt as at the eyes, it is little wonder that ob- 
jects should seem in very contact. But Home's 
other patient who suffered little and, indeed, enjoyed 
the new experience so much that he could not be 
made to keep the bandages on his eyes, said that 
things did not seem to touch his eyes, although he 
could not say definitely how far off they were. In 
all probability, therefore, apart from previous experi- 
ence, we begin without either projection of objects 
into space, or definite reference of them to the sur- 
face of the body. We have a tendency neither the 
one way nor the other ; we simply let ourselves drift 
as experience itself carries us. If the experience had 
been radically different ; if the world had been so 
constructed that objects regularly aroused pressure 
sensations without coming in contact with the skin ; 
and if luminous objects had to come up to the retina 
in order to arouse sensations of light and color, our 
interpretation of these experiences would have been 
exactly reversed. Then we should have learned to 
see things as lying against our eyes and have felt the 
touch of them as coming from a distance. 

II. How can 

But now as to the harmony which the senses show harmony in 
in reporting the more exact direction and position of re g ard to the 

t-. • l- direction of 

things. For centuries a puzzling problem has been objects? 

L 



146 



Experimental Psychology 



Claim that 
the inversion 
in the eye is 
useful and in- 
dispensable. 



Experiment 
with revert- 
ing lenses. 




Fig. 29. 



The normal inversion of the 
retinal image. 



to explain how we can see things right side up, 
although the image by which we see them is upside 
down like the picture on the ground glass of a 
photographic camera (cf. Fig. 29). Some, however, 
have taken the bull by the horns, and declared that 
this inversion of the image really simplifies the 

problem rather 
than renders it 
more obscure. 
They assert, para- 
doxically, that our 
vision of things 
as upright would 
be difficult — nay, impossible — to account for if the 
image in the eye were not inverted. The mechanism 
of the eye, they maintain, is such that it must of neces- 
sity make us perceive objects as in the reverse direc- 
tion from that of the retinal image. If the image had 
been right side up, instead of inverted as it now is, 
this reversal in our perception would still have taken 
place, and we should in that event have seen things 
upside down. Upright vision, according to this doc- 
trine, is dependent on there being in the eye an 
inverted image of the outer world. 

Recent experiments, however, are decidedly against 
this conclusion. In order to see whether the inver- 
sion of the image was really so necessary as the ad- 
vocates of this view supposed, an observer wore a set 
of lenses (as in Fig. 30) that turned the retinal image 
into an upright position for a considerable length of 
time. The results showed that an experience coming 
from such an upright image would in time be indis- 



Spatial Harmonies and Discords 147 

tinguishable from our normal experience. The first 
effect was to make things, as seen, appear to be in a 
totally different place from that in which they were 
felt. But this discord between visual and tactual 
positions tended gradually to disappear; not that 
the visual scene finally turned to the position it had 
before the inversion, but rather the tactual feeling of 
things tended to swing into line with the altered sight 
of them. The observer came more and more to refer 
his touch impressions to the place where he saw the 
object to be; so that it was clearly a mere matter 
of time when a complete agreement of touch and 
sight would be secured under these unusual condi- 
tions. And when once the sight of things and the 
feeling of them accord perfectly, then all that we 
mean by upright vision has been attained. 1 

A later experiment of a somewhat similar kind 2 Experiment 
has shown that ^ ™»" 

the agreement of 
touch and sight 
can surmount even 
greater obstacles "-•-.'[ 

than these A FIG. 30. — An arrangement of lenses giving 

an upright retinal image. 

set of mirrors was 

attached to the body by a light frame so that the 
observer viewed himself as from above his own 
head. By means of screens on this frame, vision 
was confined as nearly as possible to the view which 

1 A detailed account and discussion of these experiments will be 
found in the Psychological Review, Vols. Ill and IV. 

2 Cf. " The Spatial Harmony of Touch and Sight," Mind, October, 
1899. 




148 



Experimental Psychology 



the mirrors gave, and these mirrors reflected things 
not only out of their proper direction, but gave them, 
as well, a false distance from the observer. Here 
again the result was, at first, an utter discord in 
the spatial reports of the two senses. The whole 
body was seen in a different place from where it was 
felt; it was in fact projected at a right angle to 
the front and several feet away, as indicated by 
the dotted outline in Fig. 31. But the constant sight 




(.if*"'*..-, *.n 
•• w * \* 

* _ ^r.:fJ ***?.?«•' 

: 



Fig. 31. — Arrangement of mirrors for projecting the body into 
a false direction and distance. 



of the feet and hands, for instance, tended to pull 
the feeling of these members over into the place 
where they were seen, so that, on the third day, 
there were occasions, especially during rapid walk- 
ing, when no conflict was felt as to the place of 
the various impressions. Such a harmony, it must 
be confessed, was only occasional ; but that it could 
come at all, and particularly that it came more for- 
cibly the longer the experiment was tried, shows 



Spatial Harmonies and Discords 149 

clearly what the harmony of the tactual and the 
visual space-world consists in. The experiment in- what the 
dicates that if we were to see a thing long enough ^"and^ 
in any given place, we should, sooner or later, also touch con- 
feel it there. If the world had been so constructed slsts m ' 
that we always saw our bodies a hundred yards 
away from our point of view, our touch sensations 
would undoubtedly have taken this same position. 
The reason for it is this : there is no place in the 
visual field where we can say beforehand we ought 
to see something that we happen to be touching. 
Experience alone can teach us where it will appear. 
And similarly, before experience has guided us, there 
is no way of telling where we shall feel an object 
that we are looking at. This is why those who 
are born blind and are suddenly given sight make 
such work of touching the things they see. They 
grope and fumble and seem to hit the mark solely 
by chance. But once a person has noted the kind of 
arm movement that will bring his hand to what he 
sees, then, when the visual experience is repeated, he 
naturally expects that if he repeats his former move- 
ment he will again touch the object. If he actually 
finds the thing there, he feels that touch and sight are 
in accord ; if he finds it elsewhere, they seem to dis- Each must 
agree. The agreement is, therefore, a matter of p e e c e tat °on S ex " 
training and expectation. One can learn to expect 
anything that has been regularly experienced. So 
that a harmony of touch and sight can grow up under 
the greatest variety of circumstances, provided merely 
that the experience remains uniform long enough to 
develop fixed expectations. 



150 Experimental Psychology 

in. How can As for the size of visual objects — that in spite of 
mor» e as^o T " ^e minuteness of the image in the eye, the object 
the size of looks no smaller than it feels — doubtless some en- 
thusiast will one day try the experiment of wearing 
glasses that make all things appear twice or thrice or 
half as large as they normally do. But even before 
the fact, in the light of the experiments already tried, 
we can pretty safely say what the outcome of such an 
experiment would be. At first the visual report of 
things would contradict the report as given by the 
hand, but in time the disparity would begin to pass 
away and the observer would become conscious of 
less and less incongruity in the two kinds of experi- 
ence. If continued long enough the last vestige of 
disagreement would disappear ; things would seem to 
be of the same size whether seen or touched. For 
Absolute size the amount of surface that an object covers in the 

oftheim- has but little tQ do with th extent Q f the object 

pressions is J J 

unimportant, as we see it. The size of a thing for us is a relative 
matter ; it is its extent as compared with other things. 
Now the image in the eye, tiny as it is, gives all 
things in due proportion ; it shows me my body as 
about the size of my fellow's, it shows my arm as 
smaller than my body, my hand as smaller than my 
arm, and so on. The relations here are exactly the 
same as those that touch reports ; and so the two 
senses agree here also, in spite of the strangely differ- 
ent conditions under which they operate. The all- 
important thing is not the absolute size of visual 
The inter- images or of touch-perceptions, but that the rela- 
xations are t j ons should be kept intact — that when touch reports 

the essential L L 

thing. a thing to be half the size of another, sight should 



Spatial Harmonies and Discords 151 

tell the same story. This relation of things to one 
another is shown as well upon one scale as upon 
another. The absolute expanse of the picture is of 
no moment so far as the mere harmony of the space- 
perception is concerned, although for other considera- 
tions it is important that the image should be neither 
too large nor too small. So that here again it is a 
matter of training and expectation. Experience alone 
can teach us how much space the object we are touch- 
ing shall occupy in the visual field. Any other 
amount of space would do quite as well, provided all 
other things were in proportion. But once our ex- 
pectation has become set; once we have felt how 
large our hand, for instance, is and then have seen 
it, the two experiences stand for each other there- 
after and the two sizes seem identical. But they 
would likewise have seemed identical if the visual 
experience had been tenfold or one-tenth of what it 
now is. In all these different aspects — whether it 
be of size or distance or direction — custom and habit 
are the great forces which tend to bring a harmonious 
result out of the most contrary conditions. 

But one can dwell too exclusively on this concord The perma- 
that seems to prevail in our mental construction of n ^f dlscord f 

r of touch and 

space. The experimenter, in fact, is constantly run- sight, 
ning upon minor discrepancies in the reports of the 
senses. For instance, the smooth edge of a card 
pressed upon the arm will feel shorter than it looks ; 
or when the finger is run along a row of raised points, 
such as the blind use in reading, the distance will in 
many cases feel shorter than this same stretch does 



152 



Experimental Psychology- 



Discord is 

annulled 
only when it 
does harm. 



Space-per- 
ceptions are 
at times non- 
Euclidean. 



Examples. 



when marked off by the two terminal points alone ; 
while vision gives just the opposite effect : the dotted 
distance now seems longer than the same stretch free 
from dots. 1 These inconsistencies persist perhaps 
chiefly because they have to do with out-of-the-way 
operations, and the errors are of no practical impor- 
tance. For the spatial agreement of the senses goes 
only so far as is needed for ordinary conduct. Nature 
is no enthusiast ; she does not rush into the work of 
harmonizing our space-faculties as an end in itself 
and to be carried out with Ruskinian fidelity and 
conscience. The whole matter is dropped at the 
point where it ceases to minister to the practical 
aims of life. 

But not only does our space-experience thus have 
its unfinished nooks and corners, but at times it seems 
to do violence to the principles of at least the older 
geometry. According to Euclid, for example, the 
sum of the angles around a point is, when the angles 
are all in one plane, exactly equal to four right 
angles ; and if we enlarge certain of the angles about 
this point we do, by just so much, diminish the re- 
maining angles. Now in our actual perception this 
does not always hold. In Fig. 32 the angle A OB 
seems to be a right angle ; likewise COD, DOE, and 
EOF; and yet in the same plane there remains over 
and above these an angular distance A OF and BOC 
that is not included in them. The psychological 



1 When we take very small distances for touch, say one centimeter, 
as the total dotted distance, the illusion is in the same direction as in sight. 
Cf. Robertson, " ' Geometric-optical ' Illusions in Touch," Psychological 
Review, November, 1902. 



Spatial Harmonies and Discords 153 



effect here is in violation of our usual geometrical 
assumption that the subdivision of space does not 
alter its quantity ; for the minutely subdivided angles 




Fig. 32. 

seem greater than those not so subdivided. And, 
moreover, we see here that the enlargement of two 
of the angles AOE and BOD by subdivision does not 
appear to make them encroach upon the space occu- 
pied by the neigh- 
boring angles A OB a / 1 B 
and EOD. In the 
case of parallel lines, 
also, our experience 
actually brings to- 
gether properties C 
that are (according 
to the Euclidean 
geometry) impossible. In Fig. 33 the lines AB and 
CD seem to have the same general direction, and yet 




Fig. 33. 




154 Experimental Psychology 

the distance between them at one end (AC) seems 
greater than at their other end (BD); or if there does 
seem perhaps to be some difference of direction in 
the lines, it is hardly as much as ought geometrically 
to go with this inequality in the apparent distance 

between their ends. Psycho- 
logically, too, the possibility 
of superposition is no evi- 
dence that the figures will 
be identical when not super- 
posed. The accompanying 
forms (Fig. 34) seem of dif- 
erent size and shape, and yet 
a perfect coincidence of out- 
Fig. 34. \s lines is possible. And, finally, 

of three points lying in a straight line, the middle 
point may appear to move at right angles to this 
line, and yet it may not seem at any moment to be 
out of line with the other two stationary points. This 
experiment may be performed thus : if we arrange 
the points say vertically (as in Fig. 35) and have 
behind the middle one a set of 
short vertical bars mounted on 
a drum that is revolving slowly 
from right to left, and we ob- 
serve fixedly the middle point m 
for some time and then sud- FlG# 3S 
denly stop the passing bars, the 

middle point as we continue to look at it will then 
seem slowly to move from left to right while the other 
two points remain stationary ; and yet we can see that 
it remains all the while in line with these two points. 



Illlllll 



Spatial Harmonies and Discords 155 

The obvious objection to taking these exceptional These 
phenomena seriously would be that they are mere illu- instances 

*r ■ j j are mere illu- 

sions, and therefore have no bearing on the question sions. 

of the universal validity of mathematics. For geome- 
try is a science of real space, the objector would say, 
and these aberrations are mere appearances, not in 
the least indicating that actual space itself is irregu- 
lar or non-Euclidean. As well might you claim that 
the law of gravitation is untrue because we can dream 
of objects falling away from the earth. 

This, I feel, would be a sufficient answer to any 
one who might cite these space-illusions to show that 
geometry was untrue to the facts of the outer world 
as we empirically know them. The character of the 
outer world — of "real" space — is not affected by 
these inner vagaries of our sense-perception. 

But it would seem to me that the illusions in ques- Yet even Mu- 
tion have a bearing upon the validity of the tradi- fi° nshavea 

° r J bearing on 

tional geometry in any possible experience — the Kant's doc- 
question with which Kant has dealt so profoundly in geometry, 
his "Transcendental Esthetic." His well-known 
position is that geometry must of necessity hold true 
universally because its laws are somehow involved 
in the very structure of our sense-perception, and, 
consequently, that it would be impossible for us to 
have any experience without impressing these laws 
upon it. 1 For one who would gain this pitch of 

1 The only direct reference to illusions and to their possible bearing 
that I can lay my hands on in Kant, is the meagre and unsatisfactory 
statement in the Anthropologic (Hartenstein, p. 457) that they are 
Erscheinungen and not a part of Erfahrung, and apparently that ends 
them. 



i 5 6 



Experimental Psychology 



They are a 
kind of space- 
experience. 



To avoid the 
difficulty 
from illu- 
sions, expe- 
rience must 
be under- 
stood as of 
unlimited 
duration, 



and as a 
selected set 
of percep- 
tions. 



certainty for geometrical truths, the space-illusions in 
question would seem to deserve a little more consid- 
eration. They can hardly be ruled out of court at 
once because they are subjective and illusory, for as 
illusions they are a kind of experience. And if our 
sense-experience can in special instances depart from 
the principles of geometry, this might cast some 
doubt upon the assumption that any possible experi- 
ence would of necessity conform to Euclid. 

Our anti-geometric space-perceptions show at least 
this much, that if the older geometry is to remain 
logically valid, space-experience must be understood 
as including more than the mere sum of impressions 
that is contained in any limited stretch of time, and 
more than the mere sum of impressions gathered in 
even a practically unlimited duration. The " experi- 
ence" of five minutes may contradict the traditional 
geometry, but hardly the experience of many years. 
And what we call the experience of this longer period 
is after all a kind of idealization of what we have 
gone through. We do not give equal weight and 
value to all perceptions alike. On the contrary, we 
become impressed with the need of system and har- 
mony, and we subordinate and neglect those percep- 
tions of space that do not accord with the more 
perfect plan. If experience in this selective sense 
conforms to our geometrical theorems, the conformity 
must not be understood as due to the psychological 
character of our sense-perception in each of its par- 
ticular acts. Every single piece of space-experience 
does not come with the laws of geometry stamped 
upon it. Only in so far as our particular perceptions 



Spatial Harmonies and Discords 157 

are brought together into an ideal system, and those 
perceptions that refuse to conform are ruthlessly cut 
off, — only with this meaning of spatial experience 
would there be no conflict between psychology and 
the older geometry. What we call the experience of "Real" space 
" real " space is consequently a kind of idealization or ^^Teai" 
purified experience obtained after sifting out and dis- ized. 
carding those perceptions that are practically unreli- 
able. Practical utility — the idea of interrelating our 
objects so that they may serve as the safest guide 
for conduct — is thus a most important factor in 
making this ideal construction of space. 



The illusions we have been considering have also is real space 

a social co: 
struction ? 



a further interesting bearing on the psychology of a 



real space and of the real world. At the present 
day there is a strong tide in the socialistic direction. 
The interaction and friction of social life, rather 
than the inevitable inner development of the individ- 
ual or the interaction between the individual and his 
impersonal surroundings, are being more and more 
emphasized not only in ethics and sociology, but in 
psychology and even in metaphysics. The real 
world, the external spatial reality, for each of us, 
according to this modern tendency, is that portion 
of our total experience that is found to be common 
to us and our fellow-men. What is over and 
above this common stock is judged to be subjec- 
tive and "internal." But these space-illusions show The social 
that too much stress can be laid on our collective or * est ° freaht y 

has been 

social experience as the test of what exists in "real" made too 
space ; it is not the absolute and final test, after all. much ° ' 



158 Experimental Psychology 

For the malperceptions cited above are common in 

some degree to all normal persons, and judged by 
this standard we should have to admit that real space 
had variable mathematical features, conforming at 
one moment to certain elementary laws, and at the 
Manyiiiu- next instant defying them. As far as the observa- 
meetthis ^ on °^ a numD er of persons goes, the two outlines in 
test. Fig. 34 would have to be considered as, in reality, 

both identical and widely divergent, or as having 
these characteristics in rapid succession. Such 
normal illusions show that the properties of real 
space or of real objects are reached, not by different 
individuals unconsciously comparing notes, and giv- 
ing a heightened importance, a peculiar reality, to 
those occurrences that are common to all (though 
this may be of great influence as a cooperating 
The criterion factor), but that each individual has within him a 
dividual"*" standard by which to detect even those illusions 
that beset the race. He can judge his particular 
impressions in the light of the system of his 
experience ; and " reality " is what emerges from a 
kind of interaction and self-checking of his various 
sense-perceptions. 1 The distinction between reality 
and illusion thus is not an exclusively social dis- 
And thereby tinction. Even the testimony of the senses of others 
iifusSnseven w1 ^ not °ring one to a belief in the reality of any- 
of the race, thing that runs counter to this less tangible and 
yet more stable reality that is adjudged to lie be- 
hind his own and his neighbors' direct sensible im- 
pressions. 

1 For the more detailed discussion of the way we test and detect 
illusions, see pp. 108 et seq. 



Spatial Harmonies and Discords 159 

Our personal and immediate, as well as our social, Natural 
experience of space, then, never perfectly conforms and^u^con- 
to our ideal, or to the "reality," of space; it is a sciousness 
more or less imperfect adaptation. But if we speak ° space ' 
of adaptation, and of natural selection as part of the 
machinery by which the development has probably 
been brought about, so that those individuals who 
did not bring their senses into harmonious spatial 
cooperation were distanced in the race, it must not 
be supposed that this completely explains the mental 
process here. For our consciousness of extension is 
a fact that resists all further analysis ; it cannot 
be " deduced " from some earlier mental condition in 
which extension does not exist. 

The attempt has been made to show that extension is Extension 
a necessary result of our having different experiences ^^^lent to 
at the same time; that if a number of impressions are simultaneity. 
to be held together and at the same time kept distinct, 
they will inevitably cease to have a purely temporal 
connection and will become spatial. For time, it is 
claimed, has but one dimension ; it has length without 
breadth, and in it experiences can come only in sin- 
gle file. As soon as impressions coming together are 
also distinguished, they are then felt as side by side, 
and this is what we mean by extension. Space, then, 
according to this view, is the necessary outcome of 
simultaneous impressions distinguished and made 
into a system. 

The fallacy in this reasoning would perhaps not be Music as a 
so evident if we had no ears. For our appreciation dls P roof - 
of music shows that synchronous sense-impressions 
may be organized into a very definite system, which 



i6o 



Experimental Psychology 



Extension is 
psychologi- 
cally irre- 
ducible. 



At what stage 
of develop- 
ment does it 
appear ? 



has no essential extension whatever. In listening to 
a great orchestral composition it is true that there is 
usually some hint of space-relation. The sounds of the 
different instruments seem to come from more or less 
different directions, and to be in varying degrees vo- 
luminous. But these associations seem to be quite 
fortuitous and are not essential to the structure and 
beauty of the piece. For our space-suggestions de- 
tract, if anything, from our clear perception of the 
music, which is a structure merely of duration, in- 
tensity, and pitch. So that our appreciation even of 
a single musical chord is evidence that time itself has 
more than one dimension, and allows mental impres- 
sions to come abreast. Consequently it cannot be 
urged that our perception of space is a necessary 
outcome of sensations coming together and yet re- 
maining distinct. Harmony and d : ^cord are not ex- 
tension. In fact, space cannot be reduced to a mere 
association of non-spatial sensations. For any mere 
addition of unextended things could no more be 
equivalent to space than a sum of zeros could 
produce a quantity. 

Space as a psychological fact is therefore a unique 
addition to the mere quality, intensity, and dura- 
tion of our impressions, although it is dependent on 
these factors. Just at what point in our mental 
development this peculiar factor enters, is not known. 
Professor James and Dr. Ward are of the opinion 
that extension or voluminousness is inherent in all 
sensations, and consequently must have been there 
from the very start. In this they may or may not 
be right; for it is impossible as yet to know the 



Spatial Harmonies and Discords 161 

facts. No direct examination can be made of the 
sensations of creatures at the earliest stage, and their 
reactions are at best ambiguous. Jennings's excellent 
experiments on Paramecia 1 show that these unicellu- 
lar creatures give the same machine-like response 
regardless of the place where they are stimulated. 
They back-water and turn, always in the one direc- 
tion, no matter from what point the excitation comes. 
So that there is no positive evidence that they appre- 
ciate the position or direction of things. Another 
unicellular organism, Stentor, however, gives most 
varied responses to different stimuli, and moves in 
different directions according as it is gently touched 
upon one or another side. 

But if by the word "sensation" we intend to desig- sensations, 
nate something absolutely unorganized and elemental, lf exte ^ ded « 
— the simple material of our mental life, without form "pure." 
and void, — then the doctrine that even our earliest 
mental impressions are extended, simply means that 
a pure sensation never exists, not even at the very 
beginning; that an absolutely formless and disor- 
ganized impression is an idol of the psychological 
cave. For voluminousness in a sensation implies 
that the thing is complex; that there are differences 
held together in some sort of space-relation, vague 
though it be. If, then, the sensations of an infant 
long before birth, or of the protozoan, have in them 
the " quality of extensity," these sensations have form 

1 Jennings, "The Psychology of a Protozoan," American Journal 
of Psychology, July, 1899, with the references there to his other articles. 
For an account of his latest experiments on Stentor and Vorticella, see 
the American Journal of Physiology, October, 1902. 
M 



i6i 



Experimental Psychology 



They prob- 
ably are or- 
ganized from 
the begin- 
ning. 



But the 
organization 
need not be 
spatial. 



or arrangement, and are therefore not utterly disor- 
ganized mental stuff, ox pure sensation. x 

From the analogy of the body we should certainly 
expect something like this, — that the mind too would, 
from the beginning, be organized. For the body, 
even in the earliest single-cell form, is never abso- 
lutely simple and undifferentiated ; it is always a 
union of different parts. Why, then, should we as- 
sume that the mental life is less complex ? If there 
is any truth in the doctrine of the correspondence be- 
tween physical and mental characteristics, the psychic 
life even at its earliest stage consists in some kind 
of organization of sense-impressions. 

To infer from the analogy of the body that the 
mental materials are never quite "raw," but are 
already to some extent worked up, by no means 
determines what is the form of that earliest mental 
life. It simply implies that it has some organization 
or other, without deciding however that it has this 
special and particular form of space. For there are 
many other conceivable forms, such as the mere time- 
form, or perhaps, simpler still, mere sense of qualita- 

1 Ward, of course, would quite agree with this (cf. his Naturalism 
and Agnosticism, Vol. II, pp. 112, and following), and James, too 
(cf. his Principles of Psychology, Vol. II, pp. 3, 4). But if pure sensa- 
tions are an abstraction, as James says (and, the present writer feels, 
correctly), why should he speak of their being "realized in the earliest 
days of life" (op. cit., Vol. II, p. 7) any more than in adult life? 
Sensation is, of course, present all through life, but only as an abstract 
aspect of experience. Relatively, of course, it may be more prominent 
in infancy, but never absolutely " realized." We should hardly say, 
for instance, that the abstraction of surface without volume is realized 
in a sheet of paper but not in a block of wood (cf. note on " Matter " 
and "Form," p. 231 of this book). 



Spatial Harmonies and Discords 163 

tive contrast, that might well precede and lead up to 
this more complex fact of spatial feeling. This is a 
question of fact that cannot be settled by the a priori 
method. For there is no logical necessity that our 
sensations should be extended at the very start — 
such a necessity, for instance, as that sensations 
should have some intensity if they are to be experi- 
enced at all. And when we say, with the Kantians, 
that our experience of extension is due to some inner 
activity of the mind, it does not seem to me that we 
need assume that this particular activity is always in 
evidence, any more than that the categorical impera- 
tive is especially manifest in the earthworm or the 
oyster. But whether it is always there, as James and 
Ward suppose, or only appears at some later stage 
in the mental development, its presence, in either 
event, is an irreducible fact, and not to be regarded 
as an inevitable outcome of the merely temporal 
arrangement of our sensations. 

But here the consideration of our topic must close. Psychology 
It is already clear that the psychology of space-per- ^ * e 
ception passes insensibly into the metaphysical realm, tions of 
and into that region we must not attempt to follow it. space * 
An effort has here been made to keep at least within 
sight of the more experimental aspects of the case, — 
the way our minds obtain a picture of the expanse of 
the world, the senses on which we depend for this, the 
hints and clews by which we find out the place and 
size and shape of things, and how out of the confused 
and contradictory data there comes a consistent pano- 
rama of the world. We obtain in this way some 
hint of how this strange power within us works, but 



164 Experimental Psychology 

cannot after all by any of these means account for it 
or derive it from deeper causes. For the psychologist 
it remains, in its origin, one of the ultimate processes 
of our mental life, like our sense of temporal se- 
quence or of beauty, or our power of taking interest 
in things, or of exercising will. Whether it must of 
necessity be present in all minds, or whether if it 
were present it would reach the same results as in 
our case, psychology is unable to say. And although 
it is a power which lies so deep within us, yet it 
seems less central to the mind than many of our other 
powers. It has not the same moral place in us that 
memory or judgment or conscience has. For this 
reason it is treated lightly by the mystics, as being but 
an outer garment of the mind, a mere external sym- 
bol of our deeper spiritual states. 



CHAPTER IX 

MEMORY AND THE INFLUENCE OF TIME 

If we could thoroughly understand memory, the Memory, if 
rest of the mind would give us little trouble ; for this ^id'make 
one field practically involves all the problems of psy- ail clear, 
chology. There is often a temptation to pass over it 
lightly as a mere illustration of habit or of association ; 
and in the chapters on unconscious ideas I may have 
given the impression that there seemed to me to be 
nothing more to it than a mere repetition of a pre- 
vious mental act. But we must now do justice to 
memory and point out the marvellous intricacy of this 
familiar function. After we have done our best to 
simplify it and have regarded it as merely the return 
of a former idea, we discover that there is a flavor 
and meaning about our memories which still remains 
unexplained. The peculiar backward look which 
our recollections have is something over and above 
their mere return. Many of our ideas return, but 
they have no familiarity, we do not recognize them; 
they mean nothing historical ; they are not memories, 
therefore. So that a memory is a peculiar type of 
recurrent idea that is somehow greeted as a record 
of the past. Moreover, it is difficult to explain our 
confidence that memories have historic truth — to 
discover what it is that permits us to recognize them 

i6 5 



i66 



Experimental Psychology 



The field of 
experiment 
here. 



as copies of what has gone. In looking at the por- 
trait of a friend we can say that it is a good likeness 
because we can compare it with the man himself or 
with our recollection of him. But when we recognize 
our memories as true copies of the past, we have not 
the past itself there nor some other copy of it with 
which to compare them. And yet the recognition is 
ready and accurate. Through memory, indeed, the 
mind seems to be not only in the time-stream, but also 
outside and around it, looking down on both past and 
present as from some point remote from both. 

Into this deeper side of memory our experimental 
studies have hardly gone ; they are confined more to 
an investigation of the way our ideas fade with time 
and of other changes they undergo, and of the differ- 
ent kinds of memory we possess. In such matters 
as these, most interesting work has been done, and of 
that I shall try to give a brief report. 



Ebbing- 

haus's 

studies. 



His method 



The experiments of Ebbinghaus 1 were the pioneer 
studies of this kind ; and one of the principal prob- 
lems that he set before him was to determine the law 
according to which forgetfulness takes place. Com- 
mon experience makes it clear that time is of course 
an important factor in forgetting ; that as time elapses 
we forget more and more. The most interesting of 
Ebbinghaus's experiments had as their object the 
determination of the varying rate at which this loss 
takes place. His method of investigation was certainly 
unique. He worked with a large number of nonsense 
syllables made for the occasion by putting together, 

1 Ebbinghaus, Ueber das Gedachtniss, Leipzig, 1885. 



Memory and the Influence of Time 167 

haphazard in each case, a vowel between two con- 
sonants, — like tul, min, baf, cug,jat, — and heroically 
learned these by heart. He first found how many 
times on an average he must read over a list in order 
to be just able to repeat it without error, from memory. 
A certain length of time was allowed to pass, and then 
of course the list could not be correctly recited ; it had 
to be re-read several times before it was restored to 
the point where it could just be recited once without 
mistake. The number of re-readings thus required 
to restore it to its original clearness, compared with 
the number required to learn the list the first time, 
gave some measure of the degree of forgetfulness 
that had occurred in the interval. By varying 
this interval all the way from twenty minutes to a 
month, and carefully noting the difference in the 
result, an interesting table was obtained of the vary- 
ing speed at which oblivion comes on. Ebbinghaus and results, 
found that in a single hour over one-half of what he 
had learned had been forgotten ; after eight hours 
three-fifths was gone; after twenty-four hours, two- 
thirds ; after six days, three-fourths ; after a month, 
four-fifths ; or, in other words, more was forgotten in 
the first hour than in all the weeks succeeding. We 
might represent his results by the accompanying 
curve (Fig. 36), in which the slant indicates the rate 
at which forgetfulness ensues, the distance on the hori- 
zontal line representing the passage of time. At first 
the slant is well-nigh perpendicular, the descent being 
very sudden, and then becomes ever more gradual. 

The absolute values obtained by these experi- Their signifi 
ments have no especial significance. They must 



cance. 



i68 



Experimental Psychology 



not be understood to mean that in every case, regard- 
less of the materials with which we are dealing, we 
forget in the first hour fully one-half of anything we 
learn. Allowance must first of all be made for dif- 



24 



48 



144 



744 



FIG. 36. — Curve showing the rate of forgetfulness, according to Ebbing- 
haus's experiments. The values of the abscissas represent hours. 

ference of materials ; some things are more fascinat- 
ing than nonsense syllables ; they take a more vital 
hold of us, and consequently fade away at a much 
slower rate. And of course different absolute values 
in the results are always obtained with different per- 
sons. Some are more tenacious of a given kind of 
fact than others are. Ebbinghaus's experiments just 
described had largely to do with the particular power 
to repeat a series of muscular acts, — of articulatory 
movements ; and, in this, " ideas " and consequently 
memory as a mental act doubtless played some part, 
although probably a subordinate one. But in experi- 
ments where the recollection has to deal with more 
strictly mental things — where a person has to pass 
judgment on an impression given several minutes 
before — the results are probably, here also, in 
accord with Ebbinghaus's general principle. For 



Memory and the Influence of Time 169 

short lapses of time, however, — for a few seconds, — 
as I shall point out later, the behavior of memory is 
by no means so uniform and simple. Only the larger 
relations in Ebbinghaus's results, therefore, are sig- 
nificant and universal, namely, that the clearness of 
our recollections fades away according to a law of 
diminishing or retarded speed, whatever the speed 
itself may be. So that in the life history of ideas 
the probability of long continuance is the greater the 
longer the idea has already been able to hold its own. 
Anything that is not early devoured by time has a 
fair chance for sublunary immortality. 

Now, this rapid and then more gradual blurring of Themuta- 
our impressions as time goes by must not be confused b ' llty of our 
with the actual distortion which events often undergo 
in memory. Memory is often thought of as illustrat- 
ing the constancy of our ideas. We speak of things 
as indelibly stamped or graven on the mind, or liken 
memory to a gallery where the past is preserved in 
lasting pictures. In discussing the arguments for 
unconscious ideas, I have already criticised this view, 
chiefly on logical grounds, because of a certain inco- 
herence in the view itself. Our ideas are not solid 
things that exist during forgetfulness, but are acts 
which in many cases we may repeat and re-create as 
occasion calls. The same truth is enforced in another 
way. For if ideas were actually stored up in memory 
as permanent and stable realities, still existing during 
the interval of forgetfulness, we might expect them 
usually to appear unchanged as we recalled them at 
different times. But there is often the greatest con- 
trast between my present recollection of an event 



170 



Experimental Psychology- 



Memory 

both blurs 
and distorts. 



Some experi- 
ences shrink 
in memory, 



and my recollection of it some moments hence. The 
memory not only grows less clear, but it actually 
tells a different story as time proceeds. Now there 
is in psychology a frequent confusion of these two 
independent facts of memory, — the fact of f orgetf ul- 
ness in the sense of blurring, and of forgetfulness 
in the sense of distortion. We are at first naturally 
tempted to represent forgetfulness merely after the 
manner of a light that fades, or of a substance that 
evaporates or melts away. If the latter figure of 
speech represented the facts, there would most nat- 
urally be a change in the quantity of objects as we 
forgot them. A half-forgotten house might be but 
half the size of the same house fully remembered. 
Or a fire in memory would, perhaps, give out but a 
fraction of the warmth that we enjoyed as we sat 
beside it ; a recalled pound might weigh but an ounce, 
and so on. 

Absurd as all this sounds to the unbiassed mind, 
there have been a number of experimental facts to 
encourage the view that forgetting was equivalent to 
a diminution of the intensity or size of the original 
impression. Thus it is true that objects are judged 
to be of quite different quantity according as they 
are sensibly present or are only recalled. Sounds, 
for instance, are often judged to be less loud as 
they fade into the past. If we listen to the stroke 
of a falling ball (dropped, say, from the upper 
magnetic holder of the instrument in Fig. 37), and 
some moments later a second stroke be given which 
shall seem exactly as loud as the first, we must 
make this second stroke slightly fainter; we must 




FlG. 37. — Instrument for measuring variations in the memory 
for sounds. 



Memory and the Influence of Time 171 

have the ball fall from a point not so high, — 
perhaps from the lower ball-holder in the figure. If 
we make the second sound of the same actual intensity 
as that which has preceded, in the long run it will 
seem louder than the first one. This means of course 
that the recalled sound is represented as having less 
strength than it really possessed. But with certain while others 
intensities of light, on the other hand, the very oppo- expan ' 
site effect is observed. The remembered light seems 
brighter than it really was. And also with some 
simple space-forms, the objects seem to increase 
rather than diminish as time goes by. If a single 
square of moderate size be shown, and then, perhaps, 
twenty minutes later, a number of squares of various 
sizes be displayed, in selecting the one that seems 
to be equal to that presented earlier, too large a 
square will usually be chosen. In looking back over 
the stretch of twenty minutes the figure is thought of 
as larger than it really was. So that it is impossible 
to say that forgetting is equivalent to a quantitative 
decrease in the object forgotten — that time always 
shrinks things. It may, on the contrary, make them 
loom up the larger, as things do when seen dimly 
through a mist. The fruits of the West never seem 
to the emigrant quite equal to those of his New Eng- 
land farm. The golden age, the laus temporis acti, 
are but illustrations of this intellectual mirage which 
time produces. Some things increase while others 
decrease; memory distorts everything for better or 



1 Cf. the late Professor Kennedy's article " On the Experimental Study 
of Memory," Psychological Review, Vol. V, p. 477, for many details of 



172 



Experimental Psychology- 



No necessary 
connection 
between dis- 
tortion and 
blur. 



We cannot say that there is any necessary con- 
nection between the indistinctness and the distortion 
which comes over our recollections. We could well 
imagine a kind of mind in which things would be 
distorted in memory without becoming indistinct, or 
would grow indistinct without suffering further 
change — without seeming larger or smaller, or 
stronger or weaker, or better or worse. The relation 
of these different phenomena of memory might be 
illustrated by the human voice. Recollection is like 
a voice repeating something from an ever increasing 
distance, but which, besides growing fainter, tells a 
different story as it passes into the distance. The 
growing indistinctness in the voice would be com- 
parable to the law of forgetfulness which Ebbing- 
haus's experiments brought out. The change of story 



such experiments. As to the character of the memory-image itself, as 
set forth in my text, it should be said that there is increasing evidence 
that when a comparison is made between a present impression and one 
that occurred some time before, there often is no conscious picture of 
this earlier occurrence (cf. e.g. Bentley, " The Memory Image and its 
Qualitative Fidelity"; also Angell and Harwood, "Experiments on 
the Discrimination of Clangs for Different Intervals of Time," both 
articles in the American Journal of Psychology, Vol. XI, No. I, Octo- 
ber, 1899). 

But whenever there is a judgment with reference to a preceding im- 
pression, it would seem that we are conscious of the past occurrence in 
some form or other, if not in kind, at least symbolically or " implicitly." 
I have, therefore, continued to speak of an idea or representation of 
the past experience as involved in all these acts of comparison or 
discrimination without, however, wishing to stand by the memory- 
image view in all its rigid literalness. The representation of the past 
occurrence, whether it be in the form of a picture or of something more 
obscure, certainly undergoes alterations corresponding to what I have 
called indistinctness and distortion. 



Memory and the Influence of Time 173 

would stand for the distortion which things suffer in 
memory. It has been one of the errors of psychology 
to confuse these two aspects and to explain all the 
cases where memory minimizes things as simply due 
to the fainter voice with which memory speaks. 1 
But this is entirely beside the mark. There is 
no necessary connection between the strength with 
which words are uttered and the amount of meaning 
they convey. We can exaggerate in whispers, or 
belittle a thing in thundering tones. 

Why there should be any distortion at all is The 
not yet understood. In some cases the alteration jS ort t?!? IS 

J difficult to 

seems to be the result of an effort to make things explain, 
more uniform in memory, — to bring them nearer an 
average. A very dim light, for example, becomes 
brighter in memory; while a very bright light be- 
comes dimmer, as if by gravitation in both cases 
toward the mass or average of our experiences. 2 
But often just the opposite tendency seems to be 
present. In my own case, if two exceedingly shrill 
notes of a Galton whistle, near the upper limit of 
audible tone, be given with an interval of time be- 
tween them, even when the two are of identical 
pitch, the earlier one always seems to be the higher. 3 
The extraordinary experience, instead of being forced 
toward what is normal, becomes even more extraor- 



1 For an example of such an error, cf. von Tschisch, " Ueber das 
Gedachtniss fur Sinneswahrnehmungen," Bericht u. d. Ill Inter- 
nationalen Congress fur Psychologie, Munich, 1 89 7, p. 106. 

2 Cf. Leuba, American Journal of Psychology, Vol. V, pp. 382 et sea. 

3 From experiments on others, however, I am sure that this is not 
universally the case. 



174 Experimental Psychology 

dinary as it is recalled. Fresh and marvellous 
features are thus involuntarily added to what is 
surprising, in order to justify even to ourselves the 
effect which we remember it produced upon us. The 
same tendency is seen in the larger corporate memory 
of society, in that every great historic figure, like 
Luther or Napoleon, soon becomes the centre of a 
myth. But, again, the tendency may be still more 
irregular, so that it cannot be described either as a 
simple exaggeration or as a mere diminution. The 
same remembered fact maybe enlarged at one moment, 
only to be reduced again as it gets farther into the 
past. Thus the selfsame sound or light may, after 
two seconds, be thought of as stronger than it actually 
was, while after two minutes it may have fallen off 
and be regarded as considerably weaker than the origi- 
nal fact. 1 This, too, represents in miniature what we 
see on a larger scale in history, where for some brief 
time after an event its importance is exaggerated, 
only to be undervalued perhaps at a still later day. 

Clarification But after we have told the whole damaging truth 
in memory. a bout memory and about its tendency to distort and 
obscure the facts, we must do it justice as regards 
its occasional power to make the facts more distinct. 
After an interval has elapsed, an experience may be 
less blurred in memory than it was immediately after 
its occurrence. The clearest and most faithful view 
of things is here to be had only in the later memory- 

1 From experiments by students in the psychological laboratory of 
the University of California, an account of which will be published 
soon, I hope. 



Memory and the Influence of Time 175 

picture. It is said of experts in tasting wine or tea 
that their finest discriminations cannot be made until 
the taste is out of the mouth. And certainly any 
one who tries to observe his own mental states will 
find something similar to this ; he can tell but little 
about them until they are off at arm's length — until 
he can see them somewhat in perspective. An 
emotion or an act of will can be best scrutinized only 
in memory, so that introspection is always more or 
less a matter of retrospect. In these cases memory 
seems to offer a more stable and trustworthy basis 
of judgment than the sensible fact itself. So, in 
much of our laboratory work, it is found that the 
nicest distinctions are noticed when the two im- 
pressions which are to be compared come in suc- 
cession rather than at the same time. Two weights 
pressing on the skin simultaneously cannot be dis- 
tinguished until one of them is about one-third 
heavier than the other. But if we give them suc- 
cessively, a difference not a tenth as large as this can 
often be perceived. In music, the untutored mind 
has infinitely greater readiness in comparing the 
pitch of tones if one follows the other. For this 
reason, melody is easier of comprehension than 
harmony; few can mark at once all the different 
notes in a chord ; we appreciate its general character 
rather than its individual constituents. In the case 
of sight, it might seem that the most favorable con- 
ditions for comparing things — two colors, for exam- 
ple — would be when both were present at once. 
But even here, although the things stand there 
together, we actually compare them by running the 



i 7 6 



Experimental Psychology 



The under- 
standing 
plays a part 
in memory. 



eye back and forth, and thus make the experience of 
them successive. If we put them close together and 
look at them fixedly, both at once, the judgment is less 
secure. Now, in all these cases where comparison is 
easiest, we are in some way working by memory ; we 
have to retain some idea of the preceding impression 
and compare it with the one that follows. It is evi- 
dent, therefore, that what was said about the obscur- 
ing effect of memory as compared with the vividness 
of the original impression, cannot be the whole truth. 
The fact is that experience is a much less sensu- 
ous matter than we often believe ; the process of 
clearing up our experience — of making it stand 
vividly before us — depends by no means exclusively 
on the mere strength and liveliness of the sensa- 
tions of the moment, but on subtle processes which 
belong to the understanding. And these processes 
work slowly, and, at any given moment, over a 
comparatively limited field. We imagine that our 
minds receive things in the lump ; but even in our 
most rapid observations and with the simplest things, 
the object gradually dawns upon us ; it comes, now a 
part and, later, another part. If a very simple form 
be shown but one brief moment, — -^ of a second, 
perhaps, — the light may be strong enough to give 
a distinct effect upon the eye ; but only a portion of 
the figure is grasped by us, or we get a suggestion 
of something quite different from what really ap- 
peared. A second exposure of the same length 
partially supplements or corrects the first ; a third 
makes it still more distinct ; until with successive 
views the figure at last emerges clear. In Fig. 38, 



Memory and the Influence of Time 177 



column O gives the actual form of some outlines 
exposed in this way, the other columns (1, 2, etc.) 
give the successive drawings, all by the same observer, 
showing the apparent development with the successive 
exposures. Now 
each successive 
view hardly adds 
to the clearness of 
the impression 
upon the eye ; the 
growth in the per- 
ception is not a 
matter of more 
vivid sensation. 
The growing dis- 
tinctness in the ex- 
perience is rather 
due to our scruti- 
nizing attention — 
to our holding in 
memory what had 
been gained, and 
adding to this suc- 
cessively until we 

finally have a distinct picture of the figure. Not un- 
til we ourselves have built it up at the suggestion of 
the sensations, have we really mastered the sense- 
impressions and made them ours. This intellectual 
construction requires not only time, but it requires 
also freedom from distraction ; and when several 
things are present at once it seems impossible to give 
each that undivided attention which is possible when 






1 2. 5 4 5 


H 


f-* l-» H -H H 


fb 


i] in u 


* 


+ / ■*• ■*■ -f 


-ae- 


si* -*--*- ■*■ 


t 


L -L t <- -t. 


PI 


'-/•- q fl fl 


/cr 


/- /f S X /C 



Fig. 38. — Examples of the gradual develop- 
ment (columns 1-5) of the subjective 
image after very short exposures of an 
object shown in column O. 



The source 
of the 
increased 
distinctness. 



i 7 8 



Experimental Psychology 



A clearer 
retention pre- 
cedes the 
blurring. 



they come to us in succession. Simultaneous things, 
consequently, are more difficult to compare because 
each is clamoring for attention, and so we cannot 
scrutinize perfectly any one of them. The sense- 
materials are clear enough, but the intellectual func- 
tion is at a disadvantage. Now this intellectual part, 
this grasp of the thing, may continue to develop after 
the object is no longer sensibly present. In fact, in 
some cases, the sensible presence of the object really 
hinders our understanding of it. After it is gone, 
the attention is more elastic and alert, the various 
relations are better seen, so that the natural fading in 
memory of the sensory impression may be offset, and 
more than offset, by this retrospective clarifying 
through the understanding. In historical studies it 
has become a truism that the present is what we know 
least about ; it is all confusion, and nothing clears up 
until it can be viewed from a distance. The same 
holds true in a large measure in regard even to the 
inner experiences of our personal life. Thus it is 
extremely significant that careful experiments on the 
memory for tones, for light, and the like, often show 
a steady improvement of memory, rather than a fall- 
ing off, during the first five seconds (and sometimes 
longer) after an impression has been received. 1 Over 
against the general law that memory allows the facts 
rapidly to fade, we must therefore set up the opposing 



1 Such an improvement, for instance, is noticeable in several parts 
of the tables of Bentley {American Journal of Psychology, Vol. XI, 
p. 42), of Angell and Harwood {ibid., p. 76), as well as in those 
of Saborski (Bericht u. d. Ill Inter nationalen Congress fur Psychologic, 
p. 103) and Hirschberg {ibid., p. 107). 



Memory and the Influence of Time 179 

principle that time is frequently one of the most im- 
portant factors in clarifying our experience, and at 
first often builds up more rapidly than the other influ- 
ence pulls down. So that in all hasty or unstable 
experiences the very maximum of clearness is reached 
not while the impression is upon us, but immediately 
afterward, in a single early throb of memory. 

But the laboratory work on memory has made per- Thereten- 
haps its most interesting finds in laying bare the dif- tlon of dlffer " 
ferent ways our memory has of dealing with different materials, 
materials. Men used to think of memory as a great 
receptacle, that was, like most receptacles, indifferent 
to the kind of things put into it. A " good " mem- 
ory, it was thought, could retain anything; a poor 
one allowed everything to escape. Each of us was 
supposed to be possessed of a certain grade of reten- 
tiveness, equally tenacious or negligent (as the case 
might be) of all things committed to it. But it is 
now known that this is not the fact. With all of us 
the power of retention is very different for different 
things. And even within the limits of a single sense 
in the same person great differences may be found. 
Von Tschisch not long ago laid it down as the result 
of his students' experiments that there is a regular 
improvement of memory as we pass from the lower 
to the higher senses, that we remember best of all The usual 
the things we see and hear, and poorest the objects r f nkin s of 

° r j ^ e senses as 

of touch, while somewhere between the two comes "higher" and 
the memory for facts obtained through the muscles. 1 " lower 

1 W. von Tschisch, "Ueber das Gedachrniss fur Sinneswahrnehmung- 
en," Bericht ii. d. HI Internationalen Congress fur Psychologic, p. 95. 



180 Experimental Psychology 

hardly fits the The senses are probably not related, however, in 

facts here. ^{ s simple and orderly progression ; and whether we 

grade a sense as higher or lower depends very largely 

on the particular features that we are considering. 

We are, as a rule, undoubtedly more tenacious of the 

size of objects offered to the eyes than of those which 

touch our skin. But in respect to the memory for 

The first may the intensities of impressions, there is a reversal of 

be last. Qur usua i classification of high and low. Sight is 

now the poorest of all, hearing is only less poor, 

while the muscular sense and touch stand highest 

in the scale. 1 

It is hardly probable that the difference in the rate 
of fading of different aspects of our impressions is due 
to any peculiar quality of the impressions themselves ; 
we have no evidence as yet that some features of our 
sensations are inherently more perishable than others. 
It is rather because some have become more signifi- 
UtiHty as the cant and have a practical value and interest which 
determining Q^hers lack. Those features of our impressions which 
in the long run stand for the most, which have the 
richest and most permanent associations — these enter 
into the very weave of our mental life. The actual 
and absolute brightness, for instance, of the light 
which comes from objects is decidedly less impor- 
tant for dealing with them than are their shapes 
and sizes. The absolute brightness changes con- 
stantly with the weather or the time of day, but not 
so the form. And similarly the absolute loudness of 
sounds, while important for judging distance, is of 

1 From the results of experiments by my students, referred to a few 
pages before. 



Memory and the Influence of Time 1 8 1 

far less general importance for telling whether things 
are harmful, and for purposes of communication, than 
are the peculiar qualities and pitches of sounds. For 
this reason our power to recognize the pitch of a 
sound given some moments before, poor though it 
may be, is usually better than our ability to recognize 
the particular intensity or loudness of the sound. On 
the other hand, the weights and pressures of objects 
are often permanently characteristic of them, and are 
important for our recognition and practical treatment 
of them. The superiority of our faculty to recognize 
intensities of pressure and muscular strain as compared 
with our recollection of the intensities of sights and 
sounds is consequently a matter of biological utility. 

The importance which certain features of experi- Effect of 
ence shall have is not, however, a fixed matter and ^ lteredcon - 

' ditions. 

alike in all persons. In many cases — in the blind, 
and in the deaf, for example — the relative values 
of different kinds of impressions may be unusual. 
When a person must depend largely upon touch, 
he may have a memory for gradations and niceties 
in this field that is astonishing. If there is any truth 
in the common belief that the blind can at times dis- 
tinguish colors by feeling, it must be that different 
dyes give characteristic impressions of touch — gritty 
or smooth or cold — which are noticed and remem- 
bered and classified and associated with our color 
names, but without any true perception of the colors 
themselves. But while the memories of the blind are 
richly furnished with tactual ideas, sounds also have 
a prominent place with them. In recalling persons 
their thought circles about the voice, while with us 



1 82 Experimental Psychology- 

such recollections group about the appearance of the 
face. Their dreams, too (which are a kind of mem- 
ory), are largely in terms of sound, often running, 
even in persons not especially interested in literary 
matters, into the form of verse. 1 One of the most 
interesting things in Raehlmann's account of the 
relief of Christine Deutschmann from congenital 
blindness is the pleasure the woman took in the 
change that came over her dreams ; they became 
visual pictures where she had before of course seen 
nothing. 2 The deaf, on the other hand, when dream- 
ing or when delirious, imagine and at times actually 
produce the movements of the manual sign language 
where we should hear or use the voice. Likewise 
in the animal world, memory must take on an entirely 
different tone, and the relative tenacity for various 

1 Cf. the interesting account of the dreams of the blind, by Friedrich 
Hitschmann (himself blind), " Ueber das Traumleben des Blinden," 
Zeitschrift fur Psychologie mid Physiologie der Sinnesorgane, Vol. VIII 
(1894), p. 387- 

To illustrate the rhythm feature, he gives from the dream of an 
unliterary friend : — 

" Es trippelt Freund Hein 
In der Nacht 
In der Nacht 

Ganz sacht." 

The dreamer then murmured to himself (still asleep) : — 

" Zwolf Worte, zwolf Tote, es stimmt." 

He says that he himself often hears whole lectures in his dreams. 
The touch element, according to him, is almost if not quite absent. 
For instance, he dreams of a fire, but feels no glow from it; it seems 
to be more a matter of words. 

2 Raehlmann, " Physiologisch-psychologische Studien," etc., Zeit- 
schrift fur Psychologie und Physiologie der Sinnesorgane, Vol. II, p. 53. 



in normal 
persons. 



Memory and the Influence of Time 183 

impressions is then at times completely reversed. 
The conduct of dogs, for example, shows that their 
memory must be one vast array of odorous detail. 
Sight, instead of playing the chief role, as with us, 
is with them subordinate, a mere rudimentary sug- 
gester of possible and coming scents. When they 
must depend solely upon the sight of things, they 
behave somewhat as we do in the dark. 1 

And even in what seem to be normal persons, great Variations 
variations exist in the relative importance of sight and 
hearing in furnishing the means of recognition or 
recall. I have a friend who cannot recall or recognize 
a single simple melody, although his hearing has 
apparently the normal acuteness. The recollection 
for such things in his case is blank. He was confi- 
dent that he could recognize Dixie (he was a South- 
erner), but we soon found that the rhythm alone was 
appreciated, and if other notes were thrown into the 
same cadence it seemed to him the familiar melody. 
Another friend has a vague sense of recognition when 
certain music is played but cannot "place" the com- 

1 This subordination of sight in the dog was impressed upon me 
afresh while watching recently a fine hunting dog try to trace his way 
under circumstances where smell could not give the usual clew. An 
electric car upon which his master was riding slowed up and the dog 
jumped off, while the car with the man aboard passed on. The dog, 
of course, found at once that his master was not with him. But instead 
of following the car, — which was on a clear street and not going faster 
than he could run, while the dog's owner was in plain view on the out- 
side trying to get the dog's notice, — the dog set up a wild search for 
a ground scent, running up and down the track, and to and fro on a 
cross-street near by. This blind hunt lasted some time, until his 
master, who had alighted perhaps two hundred yards farther on, 
finally attracted the dog's attention by his call. 



value of the 
results. 



184 Experimental Psychology- 

position unless it suggests words ; through them alone 
the piece is fully recognized. Some persons can re- 
member much better what they hear ; others have 
more definite recollection of things they see. I know 
a lady who, after a single glance at an engraving never 
seen before, can answer questions as to minute details 
of the drawing that were not noticed in the short in- 
terval when the picture was shown. The answers 
are given by mentally recalling the picture and sub- 
mitting it to an examination as if it were sensibly there. 
What the explanation of this difference of memory 
type is we do not know. 
Practical Our modern psychology has thus done much to un- 

fold the variations and oddities of memory. And such 
discoveries are not merely curious, but are also of 
practical importance, especially in the conduct of the 
schools. How many children have been accounted 
stupid simply because no one appreciated the peculiar 
difficulties under which they worked ! They were 
expected to retain materials that had no affinity for 
their particular constitution. And their failure was 
counted a moral wrong, laid at the door of the will or 
of their inattention, when in reality the difficulty was 
not there at all. The present interest in child-study 
in the schools has already prepared the way for a 
more intelligent and sympathetic treatment of these 
personal differences. To a teacher interested in psy- 
chology, not as a bookish doctrine, but as a thing of 
flesh and blood, a child who cannot learn to spell 
should be regarded as a rare and inviting individual 
who may not be dismissed until he has yielded up the 
secret of his defective memory. 



CHAPTER X 

TEMPORAL SIGNS AND THE RANK OF MEMORY 

So far we have confined our attention to the vivid- How do we 
ness and fidelity of our recollections and to the differ- f h ete I m t g ne f 
ence in these respects in different minds, and in the impressions? 
same minds when dealing with different materials. 
But there is another important feature which we have 
now to consider, namely the matter of temporal signs. 
In the chapter on the consciousness of space the 
question of local signs was considered — how we are 
able to distinguish the place in the outer world from 
which various messages come, and refer each to its 
appropriate locality. There is a similar problem in 
regard to memory. How are we able to refer our 
countless memories each to its proper region of the 
past ? Each idea of the past is, while we remember 
it, a present mental act, and yet we somehow distin- 
guish the various items, and with perfect security 
say that some are of recent events while others 
belong to the early years of childhood. What is 
there in these various memories that suggests to us 
the time-order in which we should arrange them ; 
what, in other words, are their temporal signs ? 

It would be gratifying to our laboratory and me- is it accord- 
chanical-science instinct if we could truthfully assert distinctness ? 
that it is all a matter of distinctness in the various 

185 



i86 



Experimental Psychology 



But the 
vague is 
often felt to 
be recent. 



No one 
formula suf- 
fices. 



pictures, the more sharply outlined memories being 
adjudged to belong to more recent events, while the 
vaguer are felt to be of an earlier date. Distinctness 
of course is not the same as simple intensity. Very 
weak things — a whisper close to the ear — may be 
very distinct, while much louder tones coming from 
the next room may be obscure. The memories that 
are most definite, that have the most nicely marked 
details, would, according to this view, seem the more 
recent, while the obscurer ones would be referred to 
a remoter past. 

Now while many of the facts would undoubtedly 
be consonant with this view, yet as a whole they will 
not sanction so simple a rule. The recollections 
that we know are but of yesterday are often more 
vague than others that we consciously refer to an 
earlier date. Most of us could give a more coherent 
account of last summer's outing than of what occurred 
at the last dinner we attended, or could recall more 
distinctly our reading of Gulliver than of yesterday's 
newspaper. And yet we make no confusion of rela- 
tive dates. The experiences recalled more distinctly 
are nevertheless felt to belong to an earlier time. 
Distinctness consequently does not decide the order 
of memories. 

The basis of our decision here is exceedingly subtle 
and complex. It is like our judgment of the relative 
distances of objects from us : no one formula will fit 
all the facts. In determining relative distances from 
us in space, we are undoubtedly influenced by the 
intensity and distinctness and size of the objects, and 
by atmospheric and line perspective; and now one 



Temporal Signs 187 

and now another of these factors has the upper hand. 
And moreover the basis upon which we decide 
the relative distances of things in the foreground 
where binocular vision is effective, with its inequality 
in the pictures given by the two eyes, is entirely 
different from that in regard to objects far away. 
So, in ordering our memories, there are many tem- 
poral signs, and those that govern us in regard to 
recent events are not the same as for occurrences 
more remote. In memory there is a certain fore- The temporal 
ground where things stand out from each other fore £ round - 
in a kind of plastic relief, as in some temporal 
stereoscope, and we seem actually to perceive the 
time between them. The order in which we hold 
these recent events probably depends upon obscure 
gradations of emotion, or perhaps even of sensa- 
tions which accompany the memory-images and sug- 
gest to us the time to which they belong. The dis- 
tinctness of our memories may, indeed, be an impor- 
tant factor, although by no means all-important. 

But, after all, and especially when we try to interre- More remote 
late events lying in the more distant past, our main ex P enences - 
dependence is upon our knowledge of how things 
ought to go together, rather than upon simple sensa- 
tions or emotions or upon the element of distinctness. 
We learn some of the more elementary laws of nature 
and, guided by them, set up certain mnemonic land- 
marks ; and then, with these, we connect our subordi- 
nate memories, knowing, as we do, what their causal re- 
lation was, and what order they must have had. The 
psychology of space will again furnish a useful par- 
allel. A mountain is seen as lying beyond the distant 



1 88 Experimental Psychology 

bay, not because the impression of bay and moun- 
tain are each accompanied by some immediate 
local sign that tells what their relative distance is, 
but because it would violate all our knowledge 
of nature to suppose that the mountain was really 
between us and the bay, and yet the bay visible. 
We should have to suppose that the mountain 
was transparent, or was floating unsupported in the 
air. Our appreciation of the orderliness of nature, 
our conviction of causal regularity, here decides 
influence of the day. So in memory, the order of events is in 
tivesT m °~ most cases not decided by some different sensational 
or emotional sign attached to the various recollections, 
but by our conviction, based upon our knowledge of 
cause and effect, that any other arrangement would 
be an intellectual absurdity. I feel that a certain 
ocean voyage precedes a visit, say, to the city of 
Guatemala, because I know that, putting my life 
together as a whole, things will not fit one another in 
any other way. The circumstances were such that 
the voyage was, as the world goes, a precondition of 
my seeing the city at all. In the same way we refer 
our memories of childhood to a remoter past than 
those of youth, not by reason of their greater obscu- 
rity nor the different emotional tone which is un- 
doubtedly connected with each, but because it is the 
natural order of life, of which we have become 
convinced. A feeling for the intelligibility of the 
memory-system as a whole — a sense of the impossi- 
bility of understanding our past unless its order be 
thus and so — largely influences us. A subtle intel- 
lectual fondness for certain arrangements rather than 



Temporal Signs 189 

others, due in part at least to our experience and 
training, is of more influence here than any purely- 
quantitative guide. Since the memory-process is thus 
so interwoven with the judgment and the understand- 
ing (unreflective and unconscious though their opera- 
tion may be), not to speak of its connection with 
the senses and the emotions, we must give up the 
belief that memory is a distinct and separate faculty. 
Our higher intellectual functions are part and parcel 
of it. 

But this seems to conflict with the abundant evi- How can 
dence that memory comes very early in the mental ™ e ™ 01 7 be 
development. Emerson appears to be not far from mental? 
the most modern teachings of Genetic Psychology 
when he says that memory is the fundamental faculty 
without which none other could exist ; that it is the 
matrix or womb of all our higher powers. 1 But from 
the sketch just given of the various elements that 
contribute to its perfection, memory would seem to be 
too difficult and complex a thing to appear at the very 
dawn of life. So that we are now forced to ask what 
is the true rank of memory ; what is its place and 
function in our growth ? 

We are accustomed to use the word "memory" it must be 
in quite different senses, and our answer to the ques- fo^ta™* 116 
tion will depend upon the meaning which we choose, mais. 
If we mean by it a mere persistence of influences 
from the past, memory is certainly the basis of all 
development whatever. Instead of being a late 
comer, there can be no growth without it. Unless 

1 Emerson, Natural History of Intellect, Boston, 1894, p. 63. 



190 Experimental Psychology 

the creature could retain the marks of what it had 
endured, there would be no progress ; it could make 
no gains, it would at each moment return to an abso- 
lute beginning. What we call experience, from which 
we are inclined to explain so many of our mental 
acts, is itself impossible unless there be retention. 
The bare impressions of the moment, stripped of all 
associations and suggestions springing from the past, 
could of course have no meaning. The feeling of 
the passage of time, the feeling that there are real 
things outside us, not to speak of our higher percep- 
tion of law and order, are consequently dependent 
upon our power to keep at least something of what 
we have passed through. Memory in this sense may 
be traced down, almost, if not fully, to the bottom of 
the animal scale. 
Mere persist- But we must distinguish between the mere persist- 
ence vs. ence Q £ i n fl uences from the past, and a conscious re- 

conscious r 

recall. call of the past. Memory, in the higher sense, is an 

exceedingly complicated act. In order to remember, 
in this strict sense, not only must we have had the past 
occurrence continue within us, but it must actually 
influence us to the point of arousing a present idea 
and of making us recognize this as standing for a past 
event. Imagery alone is undoubtedly a compara- 
tively high achievement; but memory goes even 
farther, and makes the present images stand for a 
reality beyond them, which is past. 1 

1 I am, of course, referring here only to the clearest and most 
explicit forms of recollection, which are of a very high order of devel- 
opment. That there are lower forms which are (relatively and, per- 
haps, absolutely) imageless, I have no doubt. Cf. note, p. 172. 



Temporal Signs 191 

Now there is no good reason to believe that the Memory in 
lower forms of life ever consciously picture the past ^0^0^^ 
and recognize it as such, — ever recall preceding late. 
events and know them as belonging to an earlier date. 
Reminiscence implies a withdrawal from the storm 
and stress of life, a subordination of the present, and 
a comparatively unpractical interest in things — an 
interest that is the immediate precursor of art. For 
this reason Memory is indeed the Mother of the 
Muses. 

But in the mind of animals and very young chil- Animals' 
dren there is hardly anything approaching this free ^e^co^i- 
reminiscence. Perhaps the best illustration of what tionofob- 
their state may be is found in certain aspects of our Jects * 
dream-consciousness. In spite of its fantastic char- 
acter the dream-state is often exceedingly matter- 
of-fact and at the opposite pole from that of art. 
Imaginative though dreams may be, we are perhaps, 
while in them, usually in a practical frame of mind, 
absorbed in the affair of the moment, and without 
any desire to play with our ideas or impressions, 
or to connect them into a system of the past. And 
yet the past is of course the source from which 
the material of our dreams for the most part has 
actually come ; but we fail to recognize it or re- 
fer it to its date. In this respect we all have some- 
thing like a direct experience of the animal's plane 
of thought, so far as its mere attitude toward the past 
is concerned. Animals and babes make use of the 
past but without free recall. Their dreams, there- 
fore, are no evidence of recollection in the higher 
sense. And moreover the recognition of places and 



192 Experimental Psychology 

persons which dogs or horses display seems never 
to go so far as to excite an independent interest 
in recalling and organizing the suggestions which 
the object arouses; the mere feeling of familiarity 
itself satisfies them, and no questions are asked as 
to its cause or justification. It will not do, however, 
to be too positive in describing the mental life of 
animals, and one should always preserve a wholesome 
doubt as to the finality of his assertions here. 

Memory If so large a company of minds as the greater part 

Tdentit erSOnal °^ t ^ le ent i re animal kingdom and the younger mem- 
bers of the human family seem only to be influenced 
by the past, and not to be reminiscent, we can hardly 
say that memory in the higher sense is really a funda- 
mental process. But while many persons would per- 
haps accept the notion that memory might be absent 
in the lower forms of life and consequently should 
not be regarded as fundamental in the sense in which 
the evolutionist would understand the word, yet they 
would hold that it is fundamental for us now as moral 
beings, since it is the basis of personal identity and 
continuity. Is not memory the only thing that keeps 
our consciousness from breaking up into numberless 
fragments ; the only thing that unites our scattered 
experiences into one continuous life ? And if memory 
ever really loses its entire possessions, as it seems to 
do, in a large measure, in old age, and as many suppose 
it does, entirely, at death, would not this mean essen- 
tially the end of the particular person ? Any renewal 
of experience thereafter would be, to all intents and 
purposes, the development of a new person, and not 



Temporal Signs 193 

in any real sense a continuation of the old. The 
question of the place of memory, and of our depen- 
dence on the actual contents which memory retains, 
is therefore a weighty one for our moral future. 

To a large extent the answer is prepared in what The sources 
has already been said. I have tried to show that ^tohy. 1 
there is a development and growth in the lower forms 
of life which cannot be ascribed to a conscious repro- 
duction of the past. In animals and young children 
their past is at work in them ; their personal experi- 
ence continues to affect them, even though not con- 
sciously recalled. To retain the advantage of what 
we have experienced and to keep it as a part of our 
personal life, it is not necessary to have it before us 
in reminiscence. Benefits forgot are not the same 
as benefits annulled. We need not remember our 
school-days in order to continue to profit by what 
they gave us. The first two years of childhood are 
as much a part of us in their lasting moral worth as 
any other years of our life. It seems a more vital 
matter that an individual or a nation should have a 
good history than that it should review its history. 
I cannot therefore attribute to conscious recall the 
all-important place that some would give it. A 
distinct and continuous life may have its growth and 
moral training without our being able to look back 
and examine the sources from which that life has 
flowed. Memory, then, is not the only thing that 
keeps consciousness from breaking into atoms, or 
that binds our life into a continuous whole. 

But while conscious reminiscence is not absolutely 
indispensable for personal continuity, and while we 



194 Experimental Psychology 

Theinflu- may suppose that interruptions of memory need 
ktionsura not interrupt our intellectual and moral growth, 
conduct. is it not true that our conscious memories have an 
important influence upon conduct, and that to a large 
extent our moral stability would be upset by a loss or 
change of recollections ? I think we must admit that 
to some extent this is true. The actual contents 
which memory presents influence our acts. We do 
good to those who have done good to us. We are 
all more or less influenced by the thought of con- 
sequences that have come from former deeds. We 
hesitate to do things that are inconsistent with 
pledges given. Remembered precedent is thus an 
important factor in private life as well as in law and 
Their impor- politics. And yet, admitting the force of all this, 
tance is often we are . tQ attribute much more influence to our 

overesti- r 

mated. memories as guides of conduct than they really have. 

They are relatively surface things, and less effectual 
than they seem. Beneath all is the great under- 
current of life carrying the memories themselves 
along, rather than guided by them. For instead of 
our being the slaves of what we recall, our character 
itself largely determines what shall be remembered 
and what we shall forget, and, most important of all, 
determines the weight or force which the past event 
The scale of shall possess. For there is no fixed and inherent 
whaTcounts f° rce which a recollection exerts upon us irrespective 
of our deeper constitution. We ourselves, according 
to our affinities, lay stress on this or that particular 
item of the past and give it value and importance. 
In regard to precedents, there are really such for every- 
thing and anything you please, and we pick and choose 



Temporal Signs 195 

the one that falls in with our dominant interests; 
so that the great interests of the individual or of the 
community determine what shall be the controlling 
precedent, or with what part of our history we shall 
act consistently. For a long time, as a people, we 
remembered our own struggle for self-government 
and the words of the Declaration of Independence, 
and it seemed that these memories were guiding our 
conduct toward our neighbors; but since the naval 
fight at Manila, what an altered weight these memories 
have received ! It is not so much, then, what we 
remember, as it is the weight that we give to our 
recollections. The scale of values, after all, is what 
counts ; and while memory to some extent determines 
what the scale shall be, yet to an incomparably larger 
extent it is fixed by inner dispositions and habits that 
need not be remembered at all, in that they have 
become bone of our bone and flesh of our flesh. 

I think that from still another side memory may be in due time 
seen to be less essential to moral development and m< ; moi 7 ls 

r subordi- 

personal continuity than we are usually inclined to nated. 
admit. For with the growth of insight into the laws 
of the world, memory is being given a more and 
more subordinate place. We are indeed already in 
possession of a power which in many respects does 
the task of memory more effectually than memory 
itself. I have already spoken of the role that our 
knowledge of the order of nature plays in deciding 
the sequence and connection of our memories. But 
it really does more than that ; it supplements and 
corrects memory in various ways. Men used to 
know only so much of the past as they could per- 



196 



Experimental Psychology 



Reconstruc- 
tion of the 
past by in- 
sight. 



Even in the 
plain man, 
reason lords 
it over 
memory. 



sonally remember, or so much as was handed down 
by tradition — tradition being the corporate memory 
of society. But we have now gone beyond that 
point, and are able to know whether the tradition 
itself is right or wrong, and to see farther than its 
utmost reach. Science, working by insight into the 
laws of things, successfully reproduces the past in a 
more accurate and larger way than recollection. For 
example, by means of geology, we can recover periods 
of time long before man's life upon the earth. 

There are thus two ways of reconstructing the past 
which are psychologically and in their practical results 
quite distinct : by memory, as a kind of mechanical 
association in which there is little need of understand- 
ing the why and wherefore of events, — evening knowl- 
edge, cognitio vespertina, as it has been called ; and 
in contrast with this, there is the reconstruction by 
insight into the necessary nature of things, — morning 
knowledge, cognitio matutina, when passive memory 
is brushed aside, and fresh and vigorous intellect 
comes into play. As insight grows, memory becomes 
more and more subordinate ; the present facts them- 
selves reveal what must have been their history : we 
can thus see what they imply, much as an expert can 
glance at a thigh-bone, and tell what feet and jaws 
the beast possessed. 

It may seem fanciful perhaps to speak of the 
time when this shall be a universal art; when the 
world shall be so transparent that we may forget all 
things without loss, because we can at will reproduce 
them, having become possessed of the secret formula 
of their construction. But that is at least the " limit " 



Temporal Signs 197 

toward which we are moving ; and indeed we are 
already some distance on the way. The grasp of the 
facts by understanding rather than by memory is not 
confined to the savant ; the plain man uses it in his 
own domain. Whatever our theoretical reverence for 
memory may be, none of us now pays great practical 
respect to it ; what it tells, we accept half-heartedly 
and with suspicion, never fully believing it unless 
reason approves. I seem to recall that the facts were 
thus and so, and yet reject this and believe the op- 
posite because from certain present evidences I know 
that the event must have been otherwise. In this way, 
reason lords it over memory, modifying and rejecting 
her work without reserve. 

And yet it will not do to make the contrast too Memory is 
sharp, nor to suppose that memory can be entirely ^ an e s ^ e n n t 
laid aside. For with us at present, memory is the 
necessary means of rising superior to memory. Our 
insight is not as yet sufficient to enable us to detect 
in our immediate and present perceptions a wide 
range of unperceived facts. So that we must depend 
upon memory to furnish the larger store of experi- 
ence with which reason works. It is consequently 
through our power of recollection that we attain that 
preliminary familiarity with nature and its laws by 
which we are able later to turn upon memory, correct 
it, and even shake ourselves free from its dominion. 
The course of development, therefore, it seems prob- 
able, is from an initial state, in animals and children, 
which is without consciousness of the past, through a 
period of memory and recollection, and then onward 
toward a condition of even more perfect consciousness 



198 Experimental Psychology 

of the past than memory gives ; but by insight and 
not by mechanical retention. Memory thus stands 
between these extremes as a happy transition expe- 
dient, an easy makeshift, mercifully given us during 
the days of our ignorance, so that we may have the 
world before us without the need of understanding it. 
Some such thought seems intended by Beatrice when 
she says to Dante 1 that the angels have no need of 
memory, because there is no interruption of their 
vision ; they see all things constantly reflected in the 
divine countenance. 

1 Paradise, Canto XXIX, 11. 80, 81. 



CHAPTER XI 
IMITATION AND SUGGESTION 

It is a comparatively recent insight that imitation The worth of 
and suggestion are pervasive and significant facts. J^fy^entiy 
For a long time they were thought to be of minor im- recognized, 
portance, coming occasionally and having prominence 
only in persons of little original power. Imitation 
was counted a mark of immaturity, children and child- 
like creatures generally being almost the sole imita- 
tors ; and to imitate is still, with many, accounted a 
cause for reproach. 

But one of the great doctrinal gains of recent psy- 
chology has been the recognition that we are all imita- 
tive to the very heart ; that imitation is not a mark of 
the few and of the weak, but is really a deep trait upon 
which we may, without exaggeration, say that society 
and morality itself depend. To Tarde in France, and 
to Baldwin and Royce in this country, we are chiefly 
indebted for the development of this important truth. 
And it is largely as a resu]t of the interest they have 
aroused that at the present time one can hardly read 
a page of psychology without perceiving some appre- 
ciation of the role that imitation and suggestion play. 

Now why do we link imitation and suggestion in its connec- 
this way ? It is because they actually do lie so close tlon Wlth 

J J J suggestion. 

together that when you consider either one of them 

199 



200 



Experimental Psychology 



you are inevitably led to view the other. Imitation, 
in fact, may well be counted a special form of sugges- 
tion. But this will come out more clearly when we 
have run over some examples of these processes, be- 
ginning with the simplest and most familiar forms. 
It will then also appear that even hypnotism is inti- 
mately connected with the processes just mentioned. 



Examples of 

involuntary 

imitation. 



Tracings by 
the hand. 





I II 

FIG. 39. — I. General form of conductor's movement. II. The record of 
the subject's hand. B and E represent respectively the beginning and 
end of the movement. The arrow shows the direction of facing. 

Cases of deliberate and voluntary imitation are of 
much less psychological importance than are those of 
the opposite sort — the inevitable, involuntary falling 
into the ways of those about us, with which we are all 
familiar. In the laboratory we have a good illustra- 
tion of involuntary repetition when another's move- 
ment is intently observed. If a simple contrivance, 
something like a planchette, be arranged to write on 
smoked paper, we may obtain a record of the move- 
ment of one's hand as another traces before him the 



Imitation and Suggestion 201 

outline of some figure. The record often shows that 
the observer's hand has roughly followed the move- 
ment which he was closely watching. In Fig. 39 
the outline on the left gives the course taken by the 
conductor's hand in one such experiment, while the 
right-hand figure is taken from the record involuntarily 
made by the subject's hand while intently observing 
this movement. In this and the records below, B and 





1 11 

Fig. 40. — II shows a combination of direct and reversed imitation 
of the form in I. 



E denote respectively the beginning and the end of 
the movement. Figures 40 and 41 give similar pairs 
showing an interesting variation ; the conductor's 
movement is imitated partly in reverse order, while 
part of the figure is a direct imitation. Many of our 
acts that seem almost entirely mechanical or physio- 
logical — walking or laughing, for instance — are 
trained and modified by seeing how others do them. 



202 



Experimental Psychology 



Those who have heard the uncanny laughter of deaf 
mutes can appreciate what our own laughter would be 
like if it were not for the influence of social custom and 
good form. So tricks of speech or of gesture persist 
in certain families as if they were transmitted by direct 
inheritance, although, in fact, the children often come 




i ii 

FIG. 41. — II, imitation of I, showing in part a direct and in part 
a reversed imitation. 



How the sen- 
sible pattern 
affects us. 



by them merely through imitating their parents and 
one another. Now in all those acts which we most 
readily recognize as imitative, it is obvious that some- 
body's manner or behavior induces the like behavior 
in us. And the way in which the one person affects 
the other is, in its broader outlines at least, clear 
enough ; it is not by some immediate physical control 
that I am influenced, but only because some action 
attracts my attention so that I become conscious of 
it, and becoming conscious of it, I find that I invol- 



Imitation and Suggestion 



203 



untarily do the same. In all such cases an actual 
physical pattern is furnished, and the observer pro- 
ceeds to copy it. 

But a host of facts show that it is not always neces- A sensible 
sary to have a pattern sensibly before us. If an idea ^orSe? not 
of an action can by any other means be kept clearly necessary, 
before one, his conduct will be influenced by it quite as 
well as if it were not a mere idea but were somebody's 
real action. Several psychological experiments illus- illustrative 
trate this. If a person be made to stand erect under ex P enments - 
a blackened plate of glass or sheet of paper, and a 
wire point or sharp piece of wood be attached to his 
head so that it will quietly scratch this blackened 
surface, the swaying of his body will be recorded, 
and even when he tries to stand motionless, an intri- 
cate, irregular line will be 
formed, in appearance not 
unlike the mark left on an 
earthquake recorder. An 
example of such a record 
appears in Fig. 42, where 
the arrow marked F gives 
the direction in which the 
subject was facing. Now the 
form of this line is differ- 
ent under different mental 
conditions, and it is gen- 
erally observed that there is 

a tendency to movement in the direction of the object 
which for the moment may be claiming the subject's 
attention. If we ask him to think intently upon some- 
thing which he knows to be at his left, his whole body 




Fig. 42. — Record with subject 
standing under a smoked 
plate. 



204 Experimental Psychology- 

begins to sway toward that side. In Figs. 43 and 44 
the part of the record up to the point marked by the 
small arrow shows the normal movement without any 




Fig. 43. — The effect of attention to an object in the direction B. 

special direction of attention. The subject, whose 
eyes were all the while closed, was then told to think 
of some designated object in the direction of E\ 




Fig. 44. — Effect of attention to an object in the opposite direction 
from that in Fig. 43. 

the immediate change in the record shows the re- 
sult. And not only is the body as a whole thus influ- 
enced by the direction of attention, but similar results 



Imitation and Suggestion 205 

are obtained when we experiment with movements 
merely of the arm or hand. All of this has long been 
known from the experiments of Professor Jastrow 
working with his recorder called an " automatograph." * 
Faraday had years before arrived at somewhat similar 
results by his experiments on the phenomena of table- 
moving. He found that with the usual conditions Bearing on 
under which these movements occur — that is, with a an^mind-" 8 
circle of persons having their hands on the table and reading, 
intently thinking of its moving in a certain direc- 
tion — each person involuntarily and unconsciously 
pushes it toward the goal. By means of an appa- 
ratus of levers, he demonstrated that a considerable 
physical force was really though unconsciously ex- 
erted. 2 At the present day we are familiar with 
something similar in those games which depend upon 
"muscle-reading," and which have sometimes been 
believed to illustrate the possibility of thought-trans- 
ference. Most persons, if they really carry out the 
conditions of the game and vividly picture to them- 
selves the object that is to be found, will give mus- 
cular signs that are unmistakable to one practised in 
such things. The " thinker " either urges his compan- 
ion gently in the right direction, or else gives negative 
signs — withholds his companion from the right place, 
in his very eagerness not to betray the locality selected ; 
and this check is, when understood, as good a clew as 

1 Cf. the chapter entitled " A Study of Involuntary Movements," in 
his Fact and Fable in Psychology, Boston, 1900, p. 397. 

2 Faraday, " Experimental Investigation of Table-moving," Athe- 
na>um, July 2, 1853, cited by Scripture, The New Psychology, New 
York, 1897, p. 253. 



106 Experimental Psychology 

is needed. And even in those cases where there is 
no direct contact and consequently no possibility of 
muscle-reading in the ordinary sense, there are signs 
of another sort. The recent experiments of two 
Danish investigators, Hansen and Lehmann, 1 go to 
show that much of the alleged transfer of thoughts 
might be accounted for by hints and suggestions 
given, for instance, by changes in the mere breathing 
of the person who wishes to impress his thought upon 
another. All this indicates how responsive the body 
The body is is to the mental state. The mere idea of an act starts 
responsive to a c h am f nervous processes that finally make the 

our mental x J 

states. action real. Something that the person is thinking of 

suggests the peculiar response. The behavior is 
then the result of suggestion. In imitation in its 
commoner sense 2 there is much the same process; 
the only difference is that the pattern is not origi- 
nated from within. The suggestion in such cases 
is simply more external and less an inner product 
of our own. 
But why does But if it be true, as has been thought, that ideas 
it not re- ss over SQ reac jj]y m to movements and thus tend 

spond in all r J 

cases? to be actualized, why do we not do all things whatso- 

ever that occur to us ? One of our constant sources 
of regret is the inefficiency of so many of our good 
intentions, and, on the other hand, we happily do not 
actually perform all the foolish things of which we 
think. In many instances of this kind, however, there 

1 " Ueber unwilkiirliches Fliistern," Philosophische Studien, Vol. XI, 
p. 471. 

2 Both Baldwin and Royce, as is well known, use the term " imita- 
tion " to include much more than this. 



Imitation and Suggestion 207 

is nothing to make us doubt the original proposition 
that anything which suggests to us the thought of an 
action tends thereby to bring on the very act itself. 
When the thought remains without its proper result, 
it is usually not because there is no power in it, but 
rather because its inherent force has been offset by 
an equal or greater force in the opposite direction. 
The act does not take place, because along with the 
thought of it there comes the notion of the contrary 
action. And since both ideas tend to realization, and 
yet both cannot be realized at the same time, they 
produce a deadlock, and apparent passivity is the 
result. 

In this way checks are brought about, and the importance 
development of such checks is an exceedingly impor- tjon'and* 1 " 
tant thing. If it were not for the free and immediate choice 
rise of contrary suggestions, we should be the prey amongl eas ' 
of the first idea that occurred to us. So the arrival 
of contrary suggestions prevents headlong mechani- 
cal action, and gives us time to summon our wider 
experience and make it play upon the problem of the 
moment, and action becomes deliberate rather than 
impulsive. It seems to me erroneous to describe the 
result as a victory of one idea over another ; they do 
not fight it out among themselves, the stronger van- 
quishing the weaker. They are, rather, both can- 
didates for an alliance with the will. There is 
something like a selection by us from the various 
suggestions that arise ; we cast our volitional force 
on the side of one of them, and action in keeping 
with it takes place. 

A healthy mental life requires that there should be 



208 Experimental Psychology 

a free rise of antithetic ideas, and that we should 
prefer and emphasize the idea which seems suitable. 
But in some persons these safeguards are wanting. 
The first idea presented brings with it no opponents, 
or, if accompanied at all, it has only harmonious asso- 
ciates, and these have free play. Such persons are 
impulsive, unhesitating, unreflecting. They are often 
most efficient ; but much depends upon the kind of 
ideas first in the field. If good ideas come first, the 
absence of hesitation is a gain ; but if the ideas that 
arise are unfit, then the impulsiveness results in loss. 
The difficulty in the case of impulsive persons is, that 
the teachings of experience often obtain no hearing 
at all. 

Connection It is but a short step from such common and nor- 
nesswith 1VG ~ ma -l states as these to phenomena which at first 
hypnotism, appear to offer nothing but disconnection and con- 
trast with our ordinary consciousness. The various 
experiments in hypnotism show, on an exaggerated 
scale, much that is already familiar in impulsive per- 
sons. In the hypnotized person there is a narrowing 
of the field of consciousness, so that, for the most 
part, all ideas are excluded except such as are in har- 
mony with what the operator calls up by his words or 
signs ; and the action of the person, because spon- 
taneous contrary suggestions are checked, falls into 
accord with what has taken possession of his mind. 
He has only to be told that he is General Washington 
or Frederick the Great, and a more or less clever im- 
personation results. The ideas here, as in a simple 
impulsive or imitative action, work themselves out, 



Imitation and Suggestion 209 

unopposed, into acts. The peculiarity of the hypnotic 
state is that it shows the operation of suggestion in 
such a marked degree ; and, moreover, the ideas from 
which the action springs are usually induced from 
without, instead of arising spontaneously from the sub- 
ject's own character, as is often the case with impulse. 
There is established a strange rapport between two per- 
sons, so that the suggestions offered by the hypnotizer 
take precedence of all others, and whatever spontaneity 
there is in the patient is merely, as it were, a sponta- 
neous assistance, a ready filling-in of the bare outlines 
offered by the person in control. The action itself, 
when once the ideas are aroused, flows off unhin- 
dered according to the general law of mind, that all 
ideas, unless positively checked, tend to be expressed 
in action. The ordinary counter-suggestions — the 
doubts, the self-consciousness, the thought of the 
incongruity of the situation, all that usually makes 
it impossible for us in normal life to enact whatever 
occurs to us — these are in some way kept under in 
hypnotism, and the one isolated group of ideas comes 
to full expression. But this is only an exaggerated 
form of what occurs in ordinary imitation or sugges- 
tion. In these cases, too, an idea has forced its way 
to the centre of attention, and, excluding all rivals, 
makes us act it out. At bottom, then, suggestion and Hypnotism is 
imitation and the main facts of hypnotism are all one. f bott ° m a 

J r form of sug- 

The person whom we involuntarily imitate is one who, gestion or 
to some extent, has hypnotized us. Something in his imltatlon - 
bearing or character puts us in touch with him ; he cap- 
tures our attention, and before we know it, we are re- 
peating his acts or manner. In the case of imitation, 
p 



2io Experimental Psychology 

the suggestion is offered by another person's conduct ; 
in hypnotism it is more by word of mouth. But the 
mere difference of mode of introducing the effective 
idea into the mind of the subject is a minor matter; 
in the more essential features — that one person can 
arouse an idea of an action in another and have it 
expressed in conduct — hypnotism and imitation are 
one. Suggestion or imitation may, with this under- 
standing, be used as a convenient term for the whole 
group of occurrences. 
Analogies But I cannot drop the subject of hypnotism without 

between hyp- some f ur ther illustration of its kinship with our normal 

notic and x 

normal ac- behavior. " I hypnotized Mr. J. F.," writes a recent 
tl0n * contributor on the subject; " with one resolute com- 

mand I made him cataleptic. ' Rise,' I commanded 
him. He rose. 'Walk'; he walked. 'You cannot 
walk forward.' He tried to walk, but could not. 'You 
can only walk backward.' He began to walk back- 
ward." x But this is only an extreme form of what 
we are all experiencing every day. The same writer 
found that, without hypnotizing his men at all, they 
would carry out in a more or less direct and mechani- 
cal fashion his simple commands. And so it is in the 
larger world : some men have the power to make 
their companions feel themselves capable or incapa- 
ble of certain things, and the assurance brings about 
its own fulfilment. In many cases, men need only 
to believe that they can do a thing, and they can ; if 
they believe they cannot, the act then becomes im- 
possible for them, — a truth which Professor James 

1 Sidis, The Psychology of Suggestion, New York, 1898, p. 12. For 
his instances of suggestion without hypnotism, vide ibid., p. 35. 



Imitation and Suggestion 2il 

has turned to such striking account in his remarkable 
essay, The Will to Believe} 

Even those curious phenomena of post-hypnotic Post-hyp- 
suggestion, which to many seem absolutely unique j^ 10 sugges " 
and unprecedented, have their analogies in states of 
mind in which there is no sign of the ordinary hyp- 
notic influence. The hypnotized person is told that 
he is soon to be awakened, and thereafter, at a 
given sign, he is to perform some specified act — 
open the window or walk around his chair. The 
person is awakened, and when the occasion comes, 
although he is unable to give any clear reason why 
he should do so, he carries out the suggestion. He 
finds it more comfortable to do it than to resist the 
impulse. Something like this we are all familiar similar to in- 
with, though luckily it comes but rarely and then f^^and 
only in regard to the more trifling things of life, ideas. 
When tired or nervous we may be reasonably certain 
that our door is locked, and yet can get no peace of 
mind until we have satisfied ourselves once more 
by actual trial. Or the phrases Heldenmoral and 
Sklavenmoral flit through our mind, and although 
we are not at the moment interested the least in 
literature or ethics, but wish most of all to fall asleep, 
still the insistent question, Who has written of such 
things ? is there, and we must finally, protesting 
all the while, think up the name of Nietsche. Here 
the performance of a certain act — the recalling of 
the author's name or going to the door — is some- 
how given a force that is out of all keeping with 

1 In his The Will to Believe and Other Essays in Popular Phi- 
losophy, New York, 1898. 



212 Experimental Psychology 

the value or reasonableness of the act itself. We 
cannot justify our obedience to the suggestion on any 
ground except that it is not worth while to keep up 
the struggle ; that the quickest and simplest way to 
regain tranquillity is to yield and have done with it. 
It was evidently something of this kind that com- 
pelled Dr. Johnson, as Boswell tells us, to touch 
each post as he passed it on the street; and if by 
chance he missed one, he must return and tap it be- 
fore he could proceed. 1 We cannot in all cases say 
why an idea can gain such prominence ; in some in- 
stances, the very odiousness of the suggested act, 
however, draws our attention to it, and our efforts to 
banish it, but fix it more firmly in the mind. Thus 
we see that also in this class of acts, where the 
performance does not result simply because there 
is no opposition to it, as in so many cases of hyp- 
notism and of impulse, but because of the burr-like 
tenacity of some idea which refuses to be dropped 
until it has worked its way through — this abnormal 
kind of suggestion, too, is merely an extreme case of 
what is going on in our minds daily, but which, by 
its very familiarity, ceases any longer to attract much 
The physical attention. Even the actual physical changes which 
effects of are some ti me s produced by suggestion, — blisters or 

suggestion r J && ' 

have ana- scars, for example, by touching the skin with some 
nonnanife innocent object, like smooth glass, with the remark 

1 For other authorities and details in Johnson's case and for a num- 
ber of similar and most striking instances coming under his personal 
observation, see Dr. Hack Tuke's " Zwangvorstellungen ohne Wahn- 
ideen," Zeitschrift fur Psychologie und Physiologic der Sinnesorgane, 
Vol. II (1891), p. 95. 



Imitation and Suggestion 213 

that it is glowing hot, 1 — even these are not without 
parallels on a small scale in relatively normal states 
of mind. We can make our skin tingle by fixing 
our attention upon some portion of it; and sickness 
is often brought on by one's very concern for his 
health. 

Returning now to our normal life, it might seem Suggestion is 
as if imitation and suggestion had only to do with J^f*^ 11 " 
physical acts — movements of hands or feet, or motor affair, 
variations of speech. But this is by no means true. 
Numerous observations and experiments show that 
our more inner mental life is fully as subject to the 
effects of imitation or suggestion as are these invol- its part in 
untary movements of the body. Half of what we ^^0^" 
see and hear never comes in through our senses at 
all, but is made up outright — suggested by scraps 
and hints that do come in through our eyes and ears. 
In a foreign land, when the mind is not so ready to 
fill in all the gaps in the unfamiliar language we hear, 
one begins to appreciate how largely in our mother- 
tongue the mere act of catching the sound of the 
words, not to say their meaning, is a matter of sug- 
gestion. And in other ways we can see that as soon 
as things grow familiar and suggestive, it is im- 
possible ever to experience them again in their naked 
reality; what the bare sense-impressions call up 
to us becomes interwoven with them, and these 
additions can with difficulty be distinguished from e.g. in visual 
what is original. Thus, without experiment, we depth * 
should hardly expect that the consciousness of the 

1 Krafft-Ebing, op. cit. t pp. 28 et seq. 



2I 4 



Experimental Psychology 



Modification 
and sup- 
pression of 
sensations. 



different distances at which objects lie from us is not 
as immediately " given " as are the very colors or 
shadows of these things. And yet it is not; this 
depth effect is our own construction suggested by 
the distribution of light and shade, the direction of 
lines, and, also, by the sensations of strain and move- 
ment in the eyes. The " tactile values" in painting, 
(as Berenson well calls them), and in all our visun i 
experience, is thus a matter of suggestion. 

But, beyond the mere spatial qualities, the very 
stuff of our sensations is, by a kind of mild hypnotic 
influence, altered or suppressed. It took centuries 
for artists to see that the shadow on a colored sur- 
face was not a darker tone of the same color, but 
had usually something in it of the complementary 
hue. The natural preconception as to what the 
color of the surface ought to look like, from hav- 
ing seen it in a clearer light, made it impossible 
to see the thing aright. The imaginative filling-in 
of the "blind-spot," which exists for all of us in the 
field of view of the single eye, shows the same ten- 
dency. And Tawney by his experiments on the 
sense of touch 1 has brought out the enormous 
change that will be produced in the apparent sensi- 
bility of the skin when one is led to expect that the 
sensibility will change. So, too, if letters or figures 
be very briefly exposed to our view, it is impossible for 
one to say how much of them he has really seen 
and how much he has imagined. What, in truth, he 
does see gives some bent, starts the process of sug- 

1 Tawney, " Ueber die Wahrnehmung zweier Punkte," etc., Philo- 
sophische Studien, Vol. XIII, p. 163. 



Imitation and Suggestion 



2IJ 



gestion, and either adds to the original sense-impres- 
sion, or alters it, often in some most surprising 
way. If one try his best to copy a simple figure 
that is exposed but an instant, aiming to put down 
nothing that is not assuredly observed, it is aston- 
ishing how much will be seen that is entirely at 
variance with the figure as it really is. The accom- 
panying drawings (Fig. 45) give some hint of the re- 
sults of this process 
of subjective dis- 
tortion, the first 
column giving the 
originals that were 
actually shown, 
while the others 
are the careful 
drawings of what 
various people felt 
sure they saw. 1 
Most illusions, also, 
are illustrations of 

this trait of adding in items subjectively at the insti- 
gation of custom. The impossibility of distinguish- 
ing fact and fancy by any difference of vividness or 
of sense of reality is what makes human testimony 
upon matters of fact so untrustworthy and so much 
in need of sifting and control. Every judge and 
every juryman should take a course in the psycho- 
logical laboratory to appreciate this fully. Experi- 
ence gives us our twists and prejudices, and under its 

1 From unpublished experiments by Mr. F. G. Athearn in the labo- 
ratory of the University of California. 






B 


D 


R 


S 


v4 


<z 


^> 


>* 


_o 


y? 


^ 


^ 


J 


y 


^ 


F* 


9 


♦ 


? 



Fig. 45. — Column O gives original figures 
very briefly shown. The other columns 
show how these appeared to different 
observers. 



2l6 



Experimental Psychology- 



Suggestion 

may deter- 
mine our 
preferences. 



moulding power the outer impressions take on vari- 
ous forms. With all of us it is as it may have been 
with Polonius when Hamlet questioned him : — 

" Hamlet. Do you see yonder cloud, that's almost in shape 
of a camel? 

Polonius. By the mass, and 'tis like a camel, indeed. 
Ham. Methinks, it is like a weasel. 
Pol. It is back'd like a weasel. 
Ham. Or, like a whale? 
Pol. Very like a whale." 

But it is not in altering the play of our perceptions 
merely that suggestion makes itself felt. We find 
that our deeper processes, too, are under its control. 
Our momentary interest, our sense of the relative 
value of things, is largely a gregarious matter ; it is 
induced in us by the persons who form our society. 
On a small scale the phenomenon is illustrated by the 
effect which a single person gazing intently in a shop- 
window will have upon the passers-by, especially in a 
foreign city, where doubtless some oddities of dress 
or manner heighten his suggestive influence; you 
may select the most unpromising and commonplace 
display of goods, and very soon have quite a gather- 
ing of persons all interested in the sight. It is not 
that they wish to solve the merely intellectual prob- 
lem of what it is that you find interesting there ; 
your own attitude is catching, is involuntarily imi- 
tated, and excites its appropriate mental state in them. 
The prevalence of styles in dress, that, when the spell 
is off, look like an invention of the feeble-minded, 
illustrates the same fact. And probably the effec- 



Imitation and Suggestion 217 

tiveness of ordinary commercial advertisements lies 
less in the fact that they add to our knowledge about 
certain goods than that they simulate the voice of a 
wide circle of persons all interested in that particular 
ware and commending it ; and when throughout the 
community we seem to find such warm approval, we 
ourselves look with less distrust at the article offered 
and finally come to be among the buyers. Adver- 
tisements are effective because they produce an illu- 
sion of social approval. We are all subject, more or 
less, to the influence of " movements " or fads. Some 
become interested thereby in Japanese woodcuts, 
while others take to the study of sociology or Bud- 
dhism ; but whatever may be its form, it is an induced 
interest, and a state of mind that would be impossible 
were we not subject to contagion from those about 
us. The action of a mob that performs deeds that 
any solitary member would shrink from, is but the 
last and fiercest development of the influence which 
suggestion may have upon the single individual. 

But the mental effect of suggestion or imitation is Nor is its 
by no means always transitory, nor has it chiefly to ^^\f^ ays 
do with our hurried interests and inclinations. Our 
cool judgment, our taste, our affections, are perma- 
nently altered in this way. Through imitation, we its rdie in 
each come to possess much of what humanity has ^[0°^^.' 
accumulated. Not only does the child obtain largely 
through imitation the power of speech, with all the 
store of conceptions which that implies, but his pref- 
erences and interests, which make it possible for him 
in later life to work with his fellows, are gradually 
influenced by the constant presence of like prefer- 



218 



Experimental Psychology 



ences in his society. The interest of his parents in 
him is, as Professor Baldwin has lately shown, one 
of the main sources of the child's consciousness of 
himself. The process here is but a more important 
case of what we have, in a trivial way, in the shop- 
window experience already referred to. The inter- 
est of others excites our interest in the same thing ; so 
the child begins to take account of himself largely by 
marking the attention with which the circle of the 
family regard him. He must take notice of that 
centre to which their eyes are so constantly directed. 
His further education is very much a matter of ex- 
ample, which is but another way of saying that i^ 

in teaching; is mainly guided by imitation. The teacher's most, 
searching work consequently lies in furnishing a pat- 
tern of right interests and right appreciation of things, 
so that like attitudes of mind shall be stimulated in the 
child. Much of our respect for men comes because 

in morality, we see that others respect them, and this proper recog- 
nition of their presence is one of the foundations of 
morality and religion. The teacher may possess most 
approved pedagogical devices, and be thoroughly mas- 
ter of the subject to be taught ; but if at bottom he be 
bored by his work, nothing will quite prevent the child 
from being insensibly affected in the same way. And, 
on the other hand, it is due to the direct contagion of 
states of mind that the enthusiast, ill-equipped and 
clumsy though he may be, is often so successful in 
dealing with the young. This immediate effect of 
personality is, too, the reason why, in spite of printing- 
presses and books, the world is not yet ready to abol- 
ish the pulpit or the professor's chair. Better things 



Imitation and Suggestion 219 

than one hears from most of them are to be found on 
any shelf, and yet we rightly prefer the person to the 
book, because the words, reenforced by a living pres- 
ence, arouse the imitative powers within us in a way 
that mere print can never do. There is much sound Psychology 
psychology in some of the old dogmas of the Catholic ^ d ^ lgloja 
church which Protestants are often inclined to regard 
as empty formulas. The stress laid on the power of 
the church — on the efficacy of personal fellowship, in 
contrast with the supposed power of certain documents 
or impersonal doctrines — is in entire keeping with the 
modern perception of our dependence on example. 
The tradition must be personal rather than mechan- 
ical ; there must be a spiritual laying on of hands. 
And again, our appreciation of the value of imitation 
makes one see what deep truth there is incrusted in an- 
other of their doctrines — that the goodness of the 
saints is available for others. Not only is it available, 
but whatever gain most of us make is by a kind of 
spiritual appropriation of what others have already at- 
tained. Through imitation the gains of one become 
a common possession, without loss to him who first 
made the gain ; it is multiplied in those who avail 
themselves of it. But the facts themselves are 
even wider than the ecclesiastical doctrine ; for the 
possibility of appropriating, through imitation, the 
attainments of another is not simply a matter of 
morals or religion, in their stricter limits; it runs 
through all our life, through all planes of our in- 
tellectual growth, and even down to our bodies them- 
selves, into our very muscles and sinews. We should 
all be stronger of body if we could have only robust 



220 Experimental Psychology 

associates, and few can stand, without physical loss, 
the constant presence of invalids. 

The sinister And this leads to the fact that there are two sides 
fetation to imitation • the one beneficial, the other just the re- 
verse. There is a fascination in evil acts that causes 
them, also, to be repeated, quite as truly as in those 
of the opposite kind. Indeed, at the present day, it 
is this dangerous aspect of suggestion that has popu- 
larly been most emphasized. Not only is it often 
thought that imitation leads men to reproduce the 
bad pattern quite as frequently as the good, but the 
very fact that anything, good though it be, has come 
about at the suggestion of another, is felt to take 
somewhat from its merit. It is a sign of weakness, 
of want of originating power ; in so far as we are 
imitative we are dependent upon others and cannot 
guide them, but must be led. And so, too, in regard 
to hypnotism : the specialist is inclined to view it as 
a beneficial power, something to be used for the cure 
of the sick ; but the more widespread attitude toward 
it is, rather, one of mistrust and alarm. The appear- 
ance of hypnotism, occasionally, in the courts and in 
tales like that of " Trilby " has hinted at the possibili- 
ties of evil in it. There are those who hold that, ex- 
cepting perhaps the use of hypnotism in the cure of 
the body, its presence, whether for good or evil, is a 
disquieting thing ; it shows that we are in the power 
of others, whereas the only way to be secure is to be 
entirely self-poised, after the manner of the ancient 
stoics. 

For those who dislike the thought of dependence 



Imitation and Suggestion 221 

upon others, there really is no comfort in the univer- From our 



fellows we 
receive both 



sal influence of imitation and suggestion. The pres- 
ent appreciation of their significance is decidedly good and 
against the stoic ideal of a soul perfectly self-cen- evl * 
tred, and also against the somewhat similar Romantic 
ideal of a free and wayward personality developing 
entirely from within, taking no cue or hint from 
those about him. In laying stress upon the imitative 
function, our modern psychology is really furnishing 
excellent support for a socialistic, rather than an in- 
dividualistic, view of man. The doctrine of Leibnitz, 
in which each monad is shut off from influences from 
without, developed solely by an inner force, mirror- 
ing the universe, but standing in no vital relation 
to the other members of the system — all this is 
certainly unpsychological according to our present 
light. Whether we prefer it or not, there can be no 
doubt that in our mental, as in our physical life there 
is no possibility of isolation and solitary development. 
From our fellows, we receive both good and evil ; our 
fate to a large extent is in their hands. 

In many ways, indeed, this recognition of the essen- Respon- 
tially social character of man, which is thus reen- ^treb ls e ^_ ot 
forced by psychology, is a wholesome thing, even for dangered. 
our morals. To some the danger seems to lie in the 
fact that we are all the while discovering how little 
the individual is master of the situation, and how 
little, therefore, must be his responsibility. If in a 
certain sense we are all in the hypnotic power of our 
fellow-men, — if they do, in a degree, cast a spell 
over us and make us do their bidding, — I am not 
sure that the situation is one whit worse than in the 



222 Experimental Psychology 

older view, where each man was an independent unit, 
bound by no living tie to those about him. If my 
neighbor is not dependent upon me, and I cannot to 
some extent determine what his fate shall be, I can 
The servant feel no responsibility for him. It is as we have found 
is also lord. j n p iitics : the only way to throw responsibility on 
any one is to give him power. The difficulty is that 
we are inclined to look at the dependence as exist- 
ing in only one direction. We think of the mental 
life of the individual as swayed by the suggestions 
of his fellows, and overlook the fact that he, too, is 
a centre from which flows a counter quasi-hypnotic 
influence; he, too, is controlling them. His respon- 
sibility, which is in a way diminished when we regard 
him only as the recipient of influences, is restored 
when we see that he gives as well as takes ; and that 
since he inevitably influences others, he must answer 
for the effect which he produces. 

Originality So that imitation is, after all, but one side of the 

and imitation men t a l process. The other side is origination, which 

are insepa- r & ' 

rabie. is quite as real and demonstrable as imitation itself. 

Imitation is a mere schoolmaster to bring us to origi- 
nality. The child, through imitating others, becomes 
aware of his own capacity for a wide variety of acts 
that he otherwise would have believed were beyond 
his powers ; he finds that he is able to do what others 
do. In this way, his own strength and skill and ver- 
satility are not only cultivated, but are revealed to 
himself. Imitation, then, even when we slavishly 
copy the acts of those near us, is all the while teach- 
ing us our own capacity. But even in the earliest 



Imitation and Suggestion 223 

years we are never quite so slavish as we might be- 
lieve. All patterns do not appeal to us with equal 
force. While it is true that the prototypes of most 
of the child's acts can be found in the conduct of 
those about him, yet it is also true that a great many 
things are done in his presence which he does not 
imitate at all ; and this, of course, is especially true 
in later life. Our individuality is revealed in a sort Our selection 
of selection of the persons and kinds of behavior that ofthe P at - 

1 tern to be 

shall have power over us. I do not mean that the imitated. 
selection is always voluntary, nor is it consciously 
worked out. But there is something in us that we 
cannot attribute to mere environment — an inner 
stamp or character that makes some persons have 
weight with us while the behavior of others takes no 
hold. We find our affinities, we make our choice of 
the various forms of conduct that are offered us. 
Thus with the same set of companions we find one 
particular child picking out whatever of mechanical 
skill he finds in the company. He immediately 
seizes on their power to construct steam-engines 
or to use tools, and whatever any of his fellows 
can do in this way he imitates and makes his own. 
Another boy gathers in from the same playmates 
an entirely different set of accomplishments; upon 
him, the machinery part of their interests makes 
no impression, but all suggestions they offer which 
tend toward the collecting of things affect him 
readily, and habits of accumulation and trade, rather 
than of invention and construction, are thus encour- 
aged. No individual is absolutely plastic in the 
hands of his fellows; he soon shows his own grain. 



224 



Experimental Psychology 



Even the 

hypnotized 

subject 

reveals 

personal 

traits. 



Originality 
even in fol- 
lowing copy. 



Even the hypnotized subject carries out some sug- 
gestions better than others. So that the individual 
is not a mere recipient, a transmitter of whatever 
influences come his way, but has within him a power 
which stands over against his environment and treats 
with it on equal terms, now aiding and heightening 
its particular influence, and now resisting the sug- 
gestions which it offers. 

But the inner power of the individual is displayed 
not only in his choice of the various patterns that are 
presented to him for imitation, but also in his free 
treatment of the copy which finally counts. Very 
rarely do we find a literal repetition of what is 
offered. Even from the beginning there is a ten- 
dency to depart a little from the copy — to adapt it 
somewhat to the special circumstances and tastes of 
the individual ; so that the replica always has a turn 
in it that the original did not have. The person, 
thus, in imitating, contributes something out of his 
own character ; a novel element is introduced which 
strikes the attention of those about him ; and, if it 
accords with their own natures, is repeated by them 
and further modified and supplemented. The very 
unexpectedness of it makes it a more fascinating 
thing and increases its power. So that the differ- 
ence which we notice in the power of individuals to 
compel us to follow their example depends mainly on 
the difference in the amount of this originality which 
their acts reveal. So far as the individual is a mere 
puppet, his example counts for nothing. Imitation 
is thus always a recognition of original force and 
worth in the person who influences us ; it is, as the 



Imitation and Suggestion 225 

proverb says, the sincerest flattery. It springs from 
power, and is, therefore, not a sign merely that 
human nature is weak and plastic, but an indication 
as well that human nature has force and will. 

And of course the world is not divided into two The genius 
classes, those who imitate and those who influence f ndhls 

' times. 

others. But, rather, each person, be he genius or be 
he dolt, is in some degree both imitator and pattern. 
In some things he allows others to lead the way; 
in some things he is an example to them. And even 
the genius is an imitator, while he is putting himself 
in possession of the accomplishments of his times ; 
but having learned his trade in this way, he goes 
beyond his teachers. Genius, for this reason, does 
not produce isolated and unprecedented work, but 
comes as a culmination of much partially successful 
striving on the part of others working in the same 
line. They give him what they can, and he caps 
their work. He is, thus, neither the product of his 
times, nor is he independent of them. His general 
aim is more or less induced in him by his companions, 
and from them he learns his craftsmanship ; but he 
finally outstrips them and sets a mark which the 
others are unable to surpass. 

There is, then, no real conflict between the imita- Man is at 
tive tendency and the desire to be a source of power, ^and the* 
Only through the play of others upon us do we come clay, 
into possession of our faculties. Imitation thus paves 
the way for its own destruction. It is a kind of go- 
cart in which the infant mind learns finally to 
walk alone. The knowledge of these psychological 
factors thus brings out clearly how social and yet 
Q 



226 Experimental Psychology 

how personal a being man is ; for even his origi- 
nality is induced by others ; and, still, his imitations 
are in a way his own. Only by his inner power can 
he ever be open to suggestions from others ; a stone 
cannot be hypnotized. We must keep the two as- 
pects of suggestion before us in due proportion. We 
must not think that the individual mind is mere clay 
in the hands of society. Nor, on the other hand, 
can we, when we fully understand the import of 
imitation, ever believe that society is an accidental 
thing, and that the individual grows solely by a force 
from within. 



CHAPTER XII 

THE ENJOYMENT OF SENSATIONS AND THEIR 
FORMS 

Whatever psychology may offer in regard to Esthetics vs. 
beauty must not be considered as competing in any \£J^L of 
way with the philosophy of art. The psychological beauty, 
work here has not the same aim that aesthetics has ; 
it is concerned, first and foremost, with scientific ex- 
planations rather than with standards of judgment or 
appreciation. It is for aesthetics to define what art 
and beauty are, to determine what qualities a work 
shall have if it is to be counted a work of art ; psy- 
chology is busied with a very different problem, — 
how it is that things of beauty produce their pleas- 
urable effect. 

The psychology of the beautiful, then, remains far General 
from some of the deepest problems of art. To Jjjg^ ot 
one who is chiefly interested in this other — 
the philosophical — side, the experimental studies 
are apt to give as little satisfaction as would a 
chemist's report of the pigments used in the Sistine 
frescos, or a mineralogist's examination of the stone 
in the Victory of Samothrace. The psychological 
work is explanatory rather than appreciative, and, as 
yet, has to do with the bare rudiments of the artist's 
work — with such matters as symmetry and proportion, 

227 



11\ 



Experimental Psychology 



Why the ex- 
periments 
seem to 
slight the 
masterpieces 
of art. 



Beauty must 
first be di- 
vided into its 
elements. 



with rhythm, harmony, and the like. And even in the 
experimental study of these, only a beginning has 
been made. But this beginning is interesting, and 
already gives indications of where the final truth will 
be found. 

It might seem at first sight that the experimental 
method could most profitably be applied directly to 
great products of art like the Elgin marbles or 
Bach's Passion Music. Why not set before a person 
a work of this kind and note the character of his 
" reaction " ? Is not every artist, indeed, in some 
such way an experimenter in the realm of pleasure ? 
In a sense, yes ; but not within the scientific meaning 
of the word "experiment." For in scientific work it 
has been found that experiments are of value only in 
so far as the conditions of the experiments are rela- 
tively simple. One must not experiment with the 
universe in general, but must select from the confus- 
ing whole some single factor and discover what is its 
peculiar force. In any great work of art too many 
elements combine, and one cannot say how much of 
the total result is to be attributed to any one of them. 
The effect which the " Fates " of Phidias produces 
upon us is due not alone to the material used, and 
to the graceful curves which represent the figures 
and the drapery, but to the numberless suggestions 
which these arouse, — the times of Pericles, the Par- 
thenon, and the placid Greek religion. And each 
of these factors again contains in reality a mul- 
titude of subordinate elements. So that it is im- 
possible to deal in strict experimental fashion with 
objects which excite us in so many different ways. 



The Enjoyment of Sensations 229 

We must begin at the very beginning, with the very 
alphabet of beauty, and, if possible, gain some insight 
there into the nature of its effect upon us. 



Beginning, then, with the simplest materials of 1. The ma- 

terials c 
beauty : 



beauty, it is found that with children colors have * 



different emotional values even at an early age. It 
is not as yet entirely clear just what colors are most Color 
attractive to the infant; the results of experiments 
conflict, and probably, as with adults, there are indi- 
vidual differences. 1 But on the whole it is probable 
that the reds and yellows, which Goethe in his 
study of colors found so stimulating and which the 
savage so much enjoys, are also preferred by most 
babes. They react more promptly or strongly to 
these, or select them from among others. Blue and 
green, which, as mere impressions, are quite as 
marked, quite as vivid, in their way, as are red and 
yellow, evidently have not the charm for the primi- 
tive and childish nature that these warmer, sunnier 
hues possess. Their very association with warmth 
and vigor may in some degree contribute to this 

1 One of the sources of this conflict in experimental results is (in 
addition very likely to the personal equation of the babes) doubtless 
some lack of critical agreement as to the signs of color preference here. 
The mere power to name or to become attentive to a color, for example, 
has at times been taken as an indication that the color gave a peculiar 
pleasure. It could hardly be maintained, however, that a child's 
readier notice of a loud noise was proof that this sound was preferred 
to one of more moderate intensity. In the end, perhaps, the chief 
reliance will have to be upon the more subtle signs of enjoyment, on 
which Miss Shinn mainly depended. (See her " Notes on the Devel- 
opment of a Child," University of California Studies, Vol. I, pp. 33 
and 50.) 



230 Experimental Psychology 

effect; but doubtless the comparative rarity of the 
experience is an element in the case. Gold and red 
and yellow find the senses unjaded, since these colors 
are not constantly present ; while the blue sky and 
the green foliage are always near. The preference 
in these cases is, however, not solely sensuous ; it is 
not alone that the eye is unwearied by such tones ; 
there is, besides, the intellectual stimulation, the 
interest, which uncommon things always give. The 
savage and the child seem, also, to prefer the satu- 
rated and unmixed color, while we in our art incline 
to some softening and breaking of hues, — for in- 
stance, blue with the faintest tinge of red or yellow, — 
partly, perhaps, from a desire to imitate the colors of 
nature, which are never pure, but partly, it may be, 
to make the color less easily classed, more problem- 
atical, so that it may better hold the attention. The 
color in tapestries, the mellowness of the old masters 
of painting, gives pleasure of this kind. 1 
Musical In a similar way the purest sounds are not the 

tones. ones most used in music. The tuning-fork, after the 

first noise of the stroke is past, gives a tone like a 
pure color of the spectrum ; it is well-nigh absolutely 
unmixed. The absence of this kind of tone from 
our music may be due in part to mechanical diffi- 
culties in avoiding the initial harshness when the 
tone is struck, or to the impossibility of easily varying 

1 Professor Jastrow, from results obtained at the Chicago World's 
Fair, finds that men, in their color preference, run to blue, women to 
red. Among children, blue is far less acceptable than pink. " The 
Popular ^Esthetics of Color," Popular Science Monthly, Vol. L, 
p. 361. 



The Enjoyment of Sensations 231 

its time and strength, but there are probably deeper 

reasons as well. For the flute, which also gives a 

relatively simple and pure tone, seems characterless 

in the main. The tones that please us most — those 

of the human voice, the organ, the violin — are 

always tinged with other tones, have in them a shade 

of impurity, some dim suggestion of mere noise. 

But this foreign element never obtrudes itself; it 

never appears in its own behalf ; it serves only as a 

kind of atmosphere to enrich what is seen through it. 

The note must interest, must baffle us somewhat, or 

we reject it as tame. So that even down in the sim- Faint signs 

pie sensations of sound as well as of color, the of a u P lon of 

r ' sensation 

pleasure is due in part to the presence of some- with a non- 
thing in contrast with the mere sensations — is due sensuous ele " 

° ment. 

to the conjunction of sensation with (if we shall not 
be misled by the word) a " formal " element, as well. 
The simplest sensory part of art, its materia prima, 
already begins in this way to show faintly the marks 
that are so characteristic of the finished work, 
— the contrast of the materials, on the one hand, 
and, on the other, the order or form in which the 
materials are arranged. 1 

1 The scholastic distinction of " matter " and " form " that is so pro- 
nounced in this chapter, and, indeed, runs more or less throughout the 
entire book (although not always in these words), is not intended to 
imply that the two are separate or separable realities. The present 
writer sympathizes with the objection that has been made to the use 
of these terms, — that the two factors are interdependent, and that 
either alone is a sheer abstraction. But it is often of great practical 
service to distinguish things that are inseparable, and an abstraction is 
not necessarily a nonentity nor to be despised. Pure " matter " and pure 
" form " are two opposite limits (in a quasi-mathematical sense) between 
which a concrete reality may move, now approaching the one pole and 



232 



Experimental Psychology 



II. The 

elementary- 
forms : 



i. Rhythm. 



Imaginary 
rhythm. 



So much, then, for the more important of the 
lowest sensory materials of art. We must now pass 
over to the other side just mentioned, to the rudi- 
mentary forms that we find agreeable, more particu- 
larly to the space-forms, composed of line and sur- 
face, and to the time-forms, such as the rhythm of 
verse and of music. 

It is curious to note the craving of the mind for 
form of some kind ; so that we are never satisfied 
with separate unorganized impressions. The multi- 
tude of stars, for instance, are not left as disconnected 
points of light, but are soon grouped by us into con- 
stellations marked off by imaginary boundaries. In 
this way they become mentally more friendly and 
manageable. The very same thing goes on in the 
totally different region of sound. I have already 
referred to the fact that a succession of sounds of the 
same general kind will almost inevitably be broken 
up mentally into groups, and that each group has a 
certain organization, some of its members being 
subordinate, while others are brought to the front. 
If the sequence of sounds is reasonably uniform and 
monotonous, as with the metronome or the regular 
throbbing of a steam-engine, the sounds (as has 
already been brought out) 1 soon take on a fanciful 
rhythm, and each measure or " bar " of the rhythm 



now the other, but neither of these limits can it actually reach. The 
two are thus necessary and inseparable aspects of all reality, whose 
mutual proportions, however, may vary indefinitely (like the two 
abstractions, surface and volume, of things physical), but never to the 
exclusion of either one of the pair. 
1 Vide p. 99. 



The Enjoyment of Sensations 233 

has a duration corresponding to what we might call 
the normal pulse of consciousness, which lasts not far 
from 1 to 1.5 seconds. If a measure in this monoto- Rate of 
nous material is to be pleasing, it must take up about ^thm* 
this same absolute time of 1 to 1.5 seconds, no matter 
how many separate sounds it may contain. 1 A meas- 
ure is a group of elements that can be held in a single 
span of attention ; so that for a rhythm to be agreeable 
it must rise and fall at the rate at which this inner 
process of attention can easily go on. If a measure 
lasts too long, it is felt as a strain upon the attention ; 
if it is too rapid, it seems restless and we weary in 
trying to keep pace with it. 

At first sight it is not easy to reconcile these re- But the 
suits with the actual facts of versification and music. rhyt f hms of , . 

poetry ought 

If One repeat then to seem 

unpleasantly 

" Heard melodies are sweet, but those unheard rapid. 

Are sweeter ; therefore, ye soft pipes, play on ; 
Not to the sensual ear, but, more endear'd, 
Pipe to the spirit ditties of no tone." 

it will be found that this takes, perhaps, about twelve 
seconds, and in this time we have covered twenty 
feet, or measures, according to the ordinary scansion. 
This would give less than two-thirds of a second for 
each foot, — in verse, too, which strikes us not as 
rapid, but as rather the reverse. If in the psychologi- 
cal rhythm, as it might be called, — the natural pulse 
of attention, spoken of above — the measure is a little 
over one second, it would seem that verses like these 
should strike us as hurried rather than as deliberate. 

1 Bolton, American Journal of Psychology, Vol. VI, p. 145. 



234 



Experimental Psychology 



The psy- 
chological 
measure 
is distinct 
from the 
metrical 
"foot." 



Poetic 

rhythm then 
fits the labo- 
ratory time. 



The fact is, that the real mental measure in these 
verses does not coincide with the ordinary pentameter 
scansion at all, but proceeds in more deliberate 
fashion, having its divisions something like this, 
where the full lines show the points of more marked 
psychological division, the dotted lines the less de- 
cided boundaries : — 

" Heard melodies are sweet, | but those unheard j 

Are sweeter ; | therefore, ye soft pipes, j play on ; | 
Not to the sensual ear, | but, more endear'd, : 
Pipe to the spirit j ditties of no tone." | 

Here are nine measures, and, when read as before, 
over a second would fall to each. And thus the time 
of these important features of the rhythm corresponds 
fairly well with the wave-rate of attention. 
So, too, in the verses : — 

" She dwells with Beauty — Beauty that must die ; 
And joy, whose hand is ever at his lips 
Bidding adieu ; and aching Pleasure nigh, 

Turning to poison while the bee-mouth sips : 
Ay, in the very temple of Delight 

Veil'd Melancholy has her sovran shrine." 

We read them in perhaps seventeen seconds, and 
since there are six pentameter lines, there would be 
about a third of a second for each of the thirty feet if 
we assumed that there are as many mental pulses as 
there are verse-feet. But there are really not more 
than about twelve mental measures in these lines, so 
that each psychic foot has nearly a second and a half 
— a deliberate, unhurried rhythm. 1 

1 Some time ago my colleagues, Dr. Noble and Mr. Hart (the latter 
now at Harvard University), kindly consented to make a wider range 
of measurements than those which I had made upon myself, and of 



The Enjoyment of Sensations 235 



In more rapid verse, like — 

" Shakespeare was of us, Milton was for us, 

Burns, Shelley, were with us, — they watch from their graves! 
He alone breaks from the van and the freemen, 
He alone sinks to the rear and the slaves!" 

which takes about twelve seconds, we have sixteen 
feet, according to strict metrical arrangement; yet 
there are only eight or ten points on which there 
is any real mental stress. These it would seem are 
the real units, and the scansion feet are but ripples 
on the larger waves. So that the length of each psy- 
chological measure here, too, is a little over a second 
on the average, and consequently not far from the 
pulse time of attention as the laboratory experiments 
determine it. In music, also, in all probability, a The same 
somewhat similar agreement would be found, if we doctrme 

probably ap- 

measure, not by the artificial bar divisions, but by the plies to 
actual stretches of mental interest — the "phrases" muslc - 
(or in the slower Choral music, even the single notes), 
which are the more natural units that give the compo- 

which examples are given in the text. "With quite a variety of com- 
position (verse and prose) they found a fairly constant rate of psycho- 
logical measure for each of their three subjects, whatever the form of 
composition might be, although among the subjects themselves there 
was considerable variation. In summary they found : — 





Subject 


H. 


N. 


A. 


Average time of a single measure, 

in seconds 
Mean variation (per cent) 


1-73 
14. 


1.22 

6. 


M5 
12. 





For all three subjects the average measure was thus 1.47 sec, and the 
average variation 1 1 per cent. 



236 Experimental Psychology 

sition its psychological rhythm. The satisfaction 
which rhythm gives is, at least in part, due, then, to 
the existence of a natural pulsation in our mental life, 
and the rate of this psychic pulse roughly determines 
the rate at which pleasing rhythm may occur in art. 1 

1 Since the above was written, there has appeared the elaborate 
phonographic research by Mr. J. E. Wallace Wallin on the " Rhythm 
of Speech," in the Studies from the Yale Psychological Laboratory, 
Vol. IX (1901). Mr. Wallin, too, finds a certain approximation be- 
tween some of the larger rhythms of speech (especially of poetry) and 
the normal attention-rhythm. But the rhythm on which he lays most 
stress has as its unit the verse, or line (average duration 2.69 sec; but 
where the rhythmic effect is most marked, average 1.67 sec, — these 
being in each case the net time, i.e. the time left after subtracting 
the pauses between lines). This 1. 67 sec. verse-group, he feels, tallies 
fairly well with the normal attention-time. Less important for him is 
the shorter unit, called an " expiration group," and marked off by 
breathing pauses which do not necessarily correspond with the termi- 
nation of a line. This unit he finds on the average to be of 1.19 sec. 
duration (again omitting the silent time between the units) and shorter 
than the psychological rhythm, and therefore difficult to identify with it. 

It seems to me that in this " expiration group," rather than in the 
"verse-group," Mr. Wallin is closest to the psychological heart of the 
matter. But even here we have not as yet the real basis of the mental 
measure, as I conceive it, but only one element in it. The silent 
interval between his "groups" (average 0.44 sec, as Mr. Wallin gives 
it) seems to me an integral part of the rhythm, corresponding to the 
trough of the psychological wave; and were this added, we should 
have a time (average 1.63 sec) which is not far from the attention- 
pulse as we know it. The most significant thing in comparing the 
rate of verse-rhythm with the attention-rhythm is the time from crest 
to crest in each case, and not simply the average duration of the crests 
themselves, as in Mr. Wallin's "groups." With this change of inter- 
pretation; Mr. Wallin's results, I feel, are quite in support of the view 
offered in the text. His " expiration group," plus the silent interval, 
would correspond to my " psychological divisions of the verse," and his 
measurements (with this correction) are roughly in accord with what I 
there give, and are undoubtedly much more accurate and reliable. 



The Enjoyment of Sensations 237 

In contrast with the pleasure of rhythm which is 2. Pleasure 
present in poetry, in music, and in the dance, there ms P ace ~ 
is the gratification which comes from space-arrange- ments: 
ments. The satisfaction which we take in a beautiful s[ mpl< ? line 
curve, or even in a delicately drawn straight line, has 
by many been supposed to be not a pleasure in the 
form itself, but in the quality of the sensations which 
accompany our perception of the form. The eye, in 
following a graceful curve, these theorists hold, has 
an ease of movement, an enjoyable muscular activity, 
which an irregularly broken line does not give. The The muscu- 
muscular sensations are here supposed to be the pleas- t heoJ nSaU ° n 
ant thing, while the form itself is not enjoyable ex- 
cept indirectly as a stimulus to pleasant muscular 
feelings. This view, of course, would reduce the en- 
joyment of form to a sensuous pleasure, to a pleas- 
ure in the bare muscular sensations which enter into 
the experience, rather than to an enjoyment of the 
real form of the impression. 

It seems to me that the satisfaction which we take Evidence 
in lines is not to be so easily explained. Mere ease * hatouren - 

■' r joyment is 

of movement of the eye — the muscular sensation it- not from the 
self — is perhaps a factor in the pleasure, but a sub- e y e - musc]es - 
ordinate factor at best. In the first place, the move- 
ments of the eye, unless they become of considerable 
range or rapidity, are scarcely noticed at all, as can 
be readily shown by watching a single dim reflection 
of light on the wall of a dark room. Even when this 
light is motionless, it will often seem to move, since 
the movements of our eyes unnoticed by us are taken 
to be movements of the light. If we were so sensi- 
tive to muscular changes in the eye as some believe, 




238 Experimental Psychology 

we should attribute the movement, not to the light, 
but to our eyes. In the second place, if we close our 
eyes and roll them, the movements they make, easy 
though they be, are either absolutely pleasureless or 
are infinitely less satisfactory than the artistic lines 
we so much enjoy. And, finally, if we watch the 
actual movements which another's eye makes as he 
looks at a line, say, like that in Fig. 46, it will be 

at once noticed 
that his eye it- 
self makes no 
easy and grace- 
ful sweep along 
the contour, but 
moves in a rapid, jerky course from point to point. 
Photographic A mechanical record of the path the eye takes in 
records of the i 00 king at such a curve has an unexpected appear- 
havior. ance. A sample of such a record is given in Fig. 47, 

obtained by placing a camera so that it would catch 
the tiny image of an arc-light mirrored in the front 
surface (the cornea) of the eye as an observer swept 
his glance along the curve shown in Fig. 46. The 
heavier dots of the record show the momentary 
pauses in the eye's motion, the 
lighter lines giving its course 

as it leaped from point to point. FlG 4? _ characteristic rec- 

It is thus Seen that the eye ord of the eye's path in 

., t ,1 following the curve in 

runs a wild course, missing the Fig> 46> | om left t0 right . 
line, darting back on it again, 

moving now in straight lines, and now in curves even 
more complicated than the line it is telling us of. 
The eye's own motion is therefore entirely different 



The Enjoyment of Sensations 239 




Fig. 48. — An ugly variant of Fig. 46. 



from the form it reports. If we substitute for the 
curve in Fig. 46 an ugly variant (Fig. 48), the path 
taken by the eye is not enough different to account 
for the differ- 
ence of our feel- 
ing towards the 
line (see Fig. 
49); all of which 
goes to show 
that the muscular-sensation theory of linear grace is 
utterly untenable. Our aesthetic feeling toward vis- 
ual forms cannot be explained as an appreciation of 
the muscular sensations which such forms arouse. 1 

Why a particular form of line should be pleasing, is why ween* 
doubtless due to a combination of factors, — to a curi- j oy certain 

' lines. 

ous mixture of pleasurable feelings connected with 
intellectual, sympathetic, and volitional processes. In 
the first place a regular line is more easily grasped, 
requires less effort of attention. 
Its course throughout is in 
keeping with what any limited 
portion of the line suggests, 
and thus the mental process 
of conceiving or of under- 
standing the character of the line is easier and 
more agreeable. If there is some surprise as we 
pass along a graceful line, it is not a violent sur- 
prise, not a shock. The ugly line, however, does 
not follow any simple law ; the sight of a single 



FIG. 49.— Characteristic rec- 
ord of the eye's path in 
following the curve in 
Fig. 47- 



1 A fuller account and discussion of these experiments and their 
results appears in my contribution to the Wundt Festschrift, Leipzig, 
1902, Vol. II, p. 336. 



240 Experimental Psychology 

portion does not give us the key to the whole ; and 
for this reason it does not appear to hold together. 
Its different parts require special and disconnected 
processes of attention, and so the whole gives an 
impression of strain and lawlessness. But besides 
the greater ease in mentally grasping a graceful 
line because its parts can be brought under some 
single law or formula, its character is such as 
to call out a kind of sympathy that no ugly line 
invites. Graceful lines are by experience often 
found to be the expression of movements that 
are under perfect control, or in which there is no 
suggestion of insuperable checks and hindrances. 
The evolutions of the skater, the flight of birds, 
the movements of a hand so trained that it abso- 
lutely obeys the will, give us impressions of this 
character. So that the lines that please us are 
those that suggest, though perhaps very dimly, a 
life that is master of the situation. Such life we 
sympathize with ; it is, in a way, what we are all 
striving to attain ; we dislike anything that sug- 
gests defeat or failure to cope with circumstances. 
And what we sympathize with we imitate. We 
often feel ourselves vaguely participating in the 
movement suggested by pleasing curves ; we go 
through them ourselves, making at least incipient 
movements like those represented in the line. The 
imitative participation in what we already take 
pleasure in of course heightens the pleasure, while 
a similar participation in movements that are unat- 
tractive increases the disagreeable impression. The 
pleasurable imitation, the associations that make us 



The Enjoyment of Sensations 241 

sympathetic with what a graceful line suggests, the 
lessened tax such lines make upon the attention — 
so much, at least, enters into our enjoyment even 
of these simple forms. Our pleasure consequently 
does not come from mere muscular ease or the 
absence of sensuous fatigue in the eyes. 

We may now pass from the beauty of the single b. Combina- 
line to the satisfaction we take in the arrangement tlonso 
of two or more lines, — in harmony and proportion. 
The chief result of the experimental investigations in 
this region has been to reveal the presence of peculiar 
mathematical relations in those combinations which 
are most agreeable. Figures like the square or circle, 
which show equality of dimensions, give us a mild Symmetry, 
satisfaction because of their very regularity. They are 
special and extreme cases of that symmetry to which, 
in spite of occasional coolness, we all have a deep- 
seated attachment. Our fondness for symmetry, ex- 
cept when it is overdone and rouses us to rebellion, is 
probably not unlike our satisfaction in graceful lines : 
we like its orderliness, its intelligibility, while at the 
same time it offers always a variation of its theme, in 
that the one half repeats and yet reverses the arrange- 
ment of the other. Its very likeness in this respect Eye-move- 
to the regularity and variation in the single line has menttheor y 
tempted men, more and more, to explain its attractive- 
ness in a similar way, as due to the character of the 
eye-movements which it evokes, although in the case 
of symmetry such theories lay less stress on the mere 
ease, and more on the balance of movements, or on 
the repose of the eye which symmetrical arrange- 
ments induce. 



242 



Experimental Psychology 



and is again 
unconvinc- 
ing. 




But the reasons already given seem to make such 
a theory quite unconvincing. And, moreover, direct 
experiments indicate that symmetrical figures do not, 
to any appreciable extent, invite the 
eye to rest, or to balance of move- 
ment. Figure 50 is a copy of a photo- 
graphic record taken in the way de- 
scribed on page 238. An outline like 
that in Fig. 5 1 was placed before an 
observer, with instructions to look at 
the figure in a natural way, nothing 
of course being said in this case 
about following the line. No "bal- 
ance " of eye-movements is evident. 
The eye roves quite irregularly over 
such a figure, and yet, in spite of 
the way- 
wardness 
of these 
or ga n ic 
motions, the absolute reg- 
ularity of the external 
form itself is fully felt. 
The eye-movement theory 
here again finds no sup- 
port in the facts. The 
satisfaction, as in the case 
of single lines, does not 
lie in the muscular sensa- 
tions aroused, but in our 
appreciation of the character of the form itself. It 
is a pleasure of form, and not of sense merely. 



Fig. 50. — Record 
of the eye's 
course in look- 
ing at Fig. 51 
freely with no 
attempt to fol- 
low the outline. 
B is the begin- 
ning, E the end 
of the record. 




Fig. 51. 



The Enjoyment of Sensations 243 

But passing from symmetry with its equality of Pleasure and 
parts, distinct mathematical proportions are found JJ^tTs^" 
imbedded in other experiences which give us aesthetic 
pleasure. The musical tones, for instance, which Musical har- 
make a harmonious union are those which stand to mony ' 
each other in a very simple arithmetical ratio. In 
the harmony of the octave, the upper tone has twice 
the number of vibrations of the lower; in the har- 
monious interval of the fifth (c-g), the ratio of 
vibrations of the two tones is as 2:3; in the fourth 
(c-f) the relation is that of 3:4; in the third (c-e\ 
4:5, and so on; while the more complicated ratios, 
as that of 12:13, affect us as discords. 

No such law has been iound in the case of pairs Color 
of colors which harmonize. Colors have their rates harmon y- 
of vibration; but some colors whose rates would 
make as simple a mathematical ratio as appears in 
musical harmonies, are distinctly antagonistic, while 
other combinations whose ratios of vibration would 
correspond to a musical discord give a pleasing 
effect. 1 

But in space-forms, a study of the combinations of Proportion 
lines which seem to be in due proportion shows that ° hnes * 
here, also, there is an approach to a simple arith- 
metical relation. The most remarkable instance of 
this kind is found in our preference for particular The "gold- 
proportions in rectangles. An aesthetic tendency of en ratl °' 
this kind, having a fairly constant character, is shown 
in the general shape of book-pages, panels, pictures, 
and the like. Fechner and others have found that 
on the average the preferences of people fall near 

1 Cf. Helmholtz, Physiologischc Optik, 2d ed., pp. 399 et seq. 



244 



Experimental Psychology 



Fig. 52. — Rectangle whose 
sides have the proportion 
known as the " golden 
section" (1 : 1.618+). 



that rectangle whose shorter side is to the longer 
as this longer is to the sum of the two — a figure 
that can be constructed by making the two sides 
in the proportion of I to 1.618, or roughly, of 5 to 8 
(Fig. 52), a ratio now generally known as the " golden 
section." Experiments, moreover, on a wide variety 
of space-arrangements where 
the feeling of proportion en- 
ters, — in merely dividing a 
perpendicular line, for in- 
stance, so that the two parts 
shall seem in harmony ; or in 
selecting from ellipses whose 
axes are of different relative 
lengths the one most pleasing, 
— in all such cases there is found to be an astonishing 
partiality, not invariably for the golden section, it is 
true, but for a ratio somewhere in its neighborhood. 
The Roman cross shows the force of this feeling of 
proportion ; the cross-bar here has, for aesthetic rea- 
sons, been lowered decidedly from its position in the 
actual instrument of execution. In general, if there 
is free choice, we prefer not to have actual equality 
of the main dimensions, such as appears in the square 
or circle or the Greek cross. 

Those with strong mathematical proclivities have 
mathematics trie ^ to explain these results as due to some secret 
enjoyment coming from the mathematical instinct. 
The attractiveness of a figure which shows the 
golden proportion, according to this view, consists 
not in its immediate space-appearance, but rather 
in the peculiar arithmetical formula which the figure 



Alleged 
delight in 



this mathe- 
matical taste 



The Enjoyment of Sensations 245 

embodies. A similar theory would explain our satis- 
faction in musical harmony as likewise a gratification 
of our mathematical sense ; we, so to speak, subcon- 
sciously count the vibrations and notice that they 
stand in a simple and pleasant numerical relation. 

But if we accept this hypothesis, it would be dim- Fickleness of 
cult to see why a certain mathematical idea should 
be so gratifying when embodied in visual material, 
and yet not be especially attractive when given in 
the form of sound. Thus the golden ratio, that 
pleases us in the rectangle, is by no means the most 
satisfactory when incorporated in musical tones. 
Two tones, one of 128 vibrations and the other of 
207 vibrations, (the golden ratio), strike us as at 
least a somewhat strained harmony. And even if we 
were to suppose that in the perception of tones we 
were subconsciously aware of their vibrations, would 
it not be quite as difficult to account for our decided 
preference for a ratio such as that of 4 to 5, which 
is a musical harmony, as against the ratio of 10 to n, 
which is musically discordant ? As a bare mathemat- 
ical ratio, 10 to n is as good as any, and yet when 
embodied visually or in auditory material it would 
not be received by many of us with marked favor. 
And if further evidence were needed that the mere 
incorporation of certain arithmetical ratios is not of 
itself attractive, it could be found by experimenting 
on divisions of time according to the proportions 
which please in other fields. If we mark off two 
stretches of time so as to make the proportion of 
5 to 8, which pleases us in the rectangle, or the pro- 
portion of 4 to 5, which satisfies us in pitch, we find 



246 



Experimental Psychology 



The mys- 
ticism of 
number. 



The variety 
of causes 
here. 



that these temporal realizations of the mathematical 
idea leave us aesthetically unmoved. 

From these instances I think we may be justified 
in the generalization that the soul is not particularly 
responsive to simple mathematical ratios as such. 
The theory itself is a curious bit of mysticism — a 
remnant of the old Pythagorean philosophy of num- 
ber. But certainly it is impossible to believe that 
the numbers per se are pleasant when they are agree- 
able to us as exemplified in space, but not when pre- 
sented in time, or when one set of numbers pleases 
us in sound and an entirely different set in color. 

It is easier to find what is not the explanation of 
our choice of combinations of tones or colors or lines 
than to discover what the cause actually is. 

It is probable that in these different cases differ- 
ent factors are at work. As for musical harmony, 
and for color harmony in so far as we have in mind 
simply the agreeableness of complementary hues 
like purplish red and green, for instance, or blue and 
yellow, their explanation apparently lies mainly in 
our physiological constitution. The concordant notes 
or colors produce no nervous rasping or friction ; the 
one restores the organ which has been wearied by the 
other ; they give us, as Mr. Grant Allen expressed 
it, a maximum of stimulation with a minimum of 
fatigue. But when we turn to those beautiful com- 
binations of colors that are near akin — the similar 
but slightly contrasting tints of yellow in the daf- 
fodil, or those varied harmonies of brown in the 
late summer landscape of California — I doubt if the 
nervous resources of the eye itself are much less 



The Enjoyment of Sensations 247 

taxed in viewing these than if there were an absolute 
monotony of tone. The refreshment which the slight 
departure from the dominant note here affords is 
not so much a refreshment to the physical as to the 
mental eye. The comparison of the hues and the 
appreciation of their similarity, as well as of their 
contrast, gives us pleasure ; the recognition of their 
veiled differences adds to the pleasure we receive in 
the terms themselves. Something of this kind prob- 
ably is also present in those figures which preserve 
the golden ratio : the golden section is a golden 
mean between monotony and violent contrast. A 
happy balance is somehow struck between too little 
variety and too much. But why the balance should 
be struck at the particular point which the experi- 
ments show, no one is yet in a position to say. 

The chief result of these various experimental Ourenjoy- 
studies is, consequently, to bring out the truth that our ™^ tls 
enjoyment even of the rudiments of beauty comes sources. 
from many sources, and that it is impossible to adopt 
a single principle which will apply to every case. It 
is impossible to say that all our aesthetic pleasures 
can be reduced to sensuous enjoyment. Some of the 
pleasure certainly is an enjoyment of the sensations 
themselves ; the note of the linnet, or the pure blue 
of the sky, is good as mere sensation ; but over and 
above this there is a pleasure in the arrangement or 
form of the sensations, and in the sympathies and 
reactions which such forms call forth either directly 
or by force of association. And yet we must not 
so emphasize our enjoyment of form as altogether 



2 4 8 



Experimental Psychology- 



Higher 

and lower 
are inter- 
mingled 
throughout. 



to deny the existence of a pleasure of sense. Again, 
the principle of unity in variety, to which writers on 
aesthetics are ever recurring, is undoubtedly im- 
portant, as we found in the case of symmetry and 
of all those proportions which strike us pleasantly ; 
but alone and of itself it will explain nothing. 
Unity in variety per se is absolutely indifferent and 
unaesthetic ; a government letter-box has a kind of 
unity in variety quite as truly as a Greek vase ; and 
a railway time-table, as truly as " Lycidas " ; but 
the mere embodiment of these abstractions does not 
make them artistic. In any real work of art we 
demand that there shall be unity in variety, but we 
ask for much besides. So that the psychological 
study of the very elements of art shows that none 
of these principles can stand alone. At the very 
bottom, even in what we regard as purely sensuous 
enjoyment, certain higher factors are bound to 
enter ; we like our colors or our sounds to be com- 
plicated and not too transparent; we like them to 
surprise us ; we like them to have pleasing associa- 
tions, or to be imitative of colors and sounds which 
we know and can recognize. Thus, the tone of the 
violin gains much by its likeness to the human voice ; 
while the faultless note of the tuning-fork seems un- 
natural ; it is too crystalline and unvocal. And, 
on the other hand, even in the highest products of 
art, the purely sensuous element is still present. 
Understanding and sense, form and matter, are in 
inseparable company throughout the entire course. 



CHAPTER XIII 

COLOR AND THE DIFFERENTIATION OF THE 
FINE ARTS 

The sensuous element and the element of form Sense vs. un- 
or arrangement, although inseparable, do not affect derstandm s- 
all persons with equal force. There has always been 
more or less partisanship in regard to the two; so 
that theorists as well as artists have taken sides and 
have emphasized, now the bare sense-impressions, 
and now those aspects of things which appeal more 
strongly to other sides of our minds. Just as in ques- 
tions of philosophical doctrine there have been from 
ancient times the friends of sense, or of matter, like 
Democritus ; and, on the other hand, there have been 
those like Plato and St. Paul, who felt that the true 
life was mainly apart from sense ; — so in art, too, the 
enmity between flesh and spirit has been evident, 
and although perhaps not so vehemently argued as in 
former times, it is still present in the practice of to- 
day. Artistic reactions occur, now in favor of form 
and meaning, while again the desire is to do justice 
first and foremost to the pleasure of eye and ear. 
Impressionism, for example, is such a reaction, is an 
attempt to give its full due to the brilliant colors of 
things, regardless of whether we are able to discern 
what the things themselves are or not, and often 

249 



250 



Experimental Psychology 



The opposi- 
tion of color 
and line. 



The interest 
in space- 
forms is the 
more primi- 
tive. 



becoming in its extremists a half-mad revel in the 
immediate impression, bereft of form and intellectual 
order. 

Now, so far as the opposition is simply between 
drawing and color, our psychology is able to point to 
several facts that undoubtedly have a bearing on the 
question. There is good evidence that the sense of 
color is of later psychological development than the 
sense of form. Long before there is any vision, we 
have a muscular and tactual apparatus for perceiving 
space-arrangements. And even to the end, our color 
perception is so unstable and easily lost that we can 
well believe that the feeling for form is more deeply 
implanted in our constitution than is the sense of 
color. It may not be true that all children are color- 
blind during the earliest months of infancy, as some 
believe ; but all our lives there is a considerable por- 
tion of the field of view where we are either totally 
color-blind or are, at most, sensitive to color only of 
extreme intensity. If small colored disks be brought 
into the margin of vision so that we do not look 
directly at them, there will be found a wide zone in 
which we can see the shape of the object distinctly 
enough but not its color ; the color does not appear 
until the object is brought nearer the centre of sight. 
The whole of vision, consequently, is a vision of form, 
while only a part of it makes us aware of color. 1 
The number of persons who are color-blind even in 



1 That the analogy between color-blindness and vision with the 
border of the retina must not be pushed too far is shown by various 
recent investigations; see, e.g. Hellpach, Philosophische Studien, Vol. 
XV, p. 524, and Arnoult, Revue Philosophique, Vol. XLIV, p. no. 



Color and the Fine Arts 251 

the very centre of vision and yet retain the power 
to grasp visually the shape of things, shows how 
relatively ill-established our color vision is, in that 
it can so readily slip away, leaving us, as some have 
supposed, in our ancestral state of colorless sight. 

Now, whether or not there actually be a widespread Personal 
difference in the purely physical endowment of men ^juSto" 1 
whereby some are sensitive to color in a much higher color and 
degree than others whom we have no reason to orm * 
regard as color-blind, there certainly is a widespread 
difference with regard to the interest in the color 
of things, as compared with their form. It may, or 
may not, rest on an actual difference in our eyes 
themselves. Even apart from any such difference, of this pair, 
the interest in form is of necessity more deep-seated co 1 lor 1S more 

J r a luxury. 

than that of color ; it is less a luxury and more a 
factor that is indispensable if one is to deal with 
his environment and live. The characteristic marks 
of things by which we recognize them and treat 
them as friend or foe are given in their form ; the 
color is relatively unimportant. How much more 
the colorless photograph tells — of scenery and of 
portraiture, for instance — than any possible color 
chart, which should never so faithfully set forth in 
columns the tints in a particular landscape or in a 
person's face, but tell nothing of the form and 
arrangement of these colors. For this reason, we 
must attend to the shapes of things or die, whereas 
an interest in color is rarely, if ever, forced upon us ; 
it is not one of the fundamentals. 

Now in this regard, while most persons keep well 
within the lines of common utility — in that the form 



252 



Experimental Psychology 



Exaggerated 
development 
in each of 
these two 
directions. 



Colored 
sounds. 



Space- 
thinking. 



of things interests them, but not unduly, — there are 
others whose interest takes a turn that is as yet 
apparently useless and inexplicable. We have one 
group made up of persons for whom color has in 
some way come to have an exaggerated importance, 
while there are others in whose mental life spatial 
form plays an abnormally prominent r61e. Such a 
division seems to be borne out by certain phenomena, 
noticed in recent years, which show in many indi- 
viduals a curious tenacity for pure spatial relations, 
so that all things, even when not spatial, are persist- 
ently represented as having this form ; while others 
think of things preferably in terms of color, although 
the objects themselves may be colorless. Some per- 
sons represent all sounds as having color; an ac- 
quaintance of mine thinks of the higher tones of the 
musical scale as yellow, while the lower tones have 
a purplish cast. Such persons may hear all words as 
colored, and even the separate elements of words 
have their separate tinge. In the word " size," for 
example, one of my students hears the opening si as 
yellow passing into orange, while the closing z sound 
is distinctly red. Here color has evidently come 
to the mental foreground and would monopolize the 
attention. In the other type of mind everything runs 
to spatial form. All ideas here have their spatial 
symbols : — in a case I know of, Wednesday is 
always represented by a window with draped cur- 
tains, while Monday is thought of as a triangle 
with a dot in the centre. A large number of per- 
sons always picture the common series — the months, 
the alphabet, the number series — as arranged in 




Fig. 53. — Wire model of a mental number-form. 




FIG. 54. — Wire model of a mental number-form. In this and the preceding 
figure, the vertical supports are not a part of the subjective form. 



Color and the Fine Arts 253 

some very definite shape, often exceedingly intri- 
cate and with no apparent logical appropriateness, 
but yet quite constant for them as far back as 
their memory reaches. The accompanying number- 
forms (Fig. 53 and 54) are those of two of my friends 
who belong to this type. The second of these forms 
belongs to one who is especially interested in archi- 
tecture, which would be additional evidence of the 
r61e that spatial, colorless form plays in his mental 
world. A peculiarity of this same number-form (to 
which writers, so far as I know, have made no refer- 
ence) is that with the higher numbers the person 
changes his point of view, apparently turning the 
form, as a whole, around, and looking at it from an 
opposite side. 

But while it might be questioned whether later The diver- 
investigation will show that there is the significance g er ^ ofco101 

& and drawing 

here conjectured in these curious tricks of mind, in art. 
there are certainly the two classes of men : the larger 
group who keep to the great underlying interest in 
form — the interest to which nature herself early 
trains us ; the other and smaller group who have 
developed in a most unpractical way a peculiar inter- 
est in color. This difference makes us understand 
better the different excellences of artists, as well as 
the different sympathies which the laity feel with 
contrasting schools of pictorial art. According as 
the chief pleasure is taken in one or the other 
side, do men demand that the drawing or the col- 
oring of a picture shall not be deficient. And for 
a like reason, there are artists whose strength lies 
in color, like Rubens or the Venetians, while others 



2 54 



Experimental Psychology 



frankly turn to sculpture or line-work, or when they 
use pigments they find their chief joy in producing 
effects in which color plays a less essential part, and 
contrast of shadows and light, or the modelling of 
figures, is the main interest, as in the work of Rem- 
brandt or the frescos of Michelangelo. 



Rivalry of 
the sensuous 
and the inter- 
connective 
element. 



Nature 
forces us to 
subordinate 
one or the 
other of 
these. 



But if the opposition between color and pure space- 
arrangement as shown in such instances as these were 
the whole story, there would be perhaps some little 
ground for the feeling already referred to that the 
sensuous and the relational, or "formal," side of art 
are in conflict. But the great historic doctrine of an 
opposition and even an antagonism between sense 
and understanding has a firmer foundation than this. 
For it is found that the economy of the mind is such 
that if the sensuous element comes into prominence, 
it does so at a certain cost. Great vividness of sense- 
impressions hinders the suggestiveness, the meaning, 
of the impressions ; and, on the other hand, our grasp 
of the interconnection of things — the play of under- 
standing over and around an object — takes the life 
from the sensations which the object gives. So that 
nature herself forces a choice upon us, and will not 
give unstintingly of both at once. Thus if we would 
see in any object its pure color in all its native force, 
we must in some way obscure the meaning of the 
color, either by slightly turning the head or by 
looking at a broken or inverted image of the thing. 
Notice, at dinner, what fresh pink color your friends' 
faces show when reflected in the curved surfaces of 
the silver ; or from your study-window see how much 



Color and the Fine Arts 255 

more violet are the shadows under the trees when 
you draw your curtains and see the landscape, not 
as foliage and earth and shade, but as meaningless 
splashes of color through the white curtains them- 
selves. And, further, we can never appreciate so 
well the subtler relations of things if the objects 
themselves impress our senses too strongly. If we 
are close to a speaker addressing a large audience, 
the mere force of the sound hinders our thought; 
the auditory experience is so prominent that the full 
association, the significance, of his words, less freely 
arises. And the same is true if we are too near an 
orchestra ; the connection, the unity of the effect, 
is lost in the individual sounds; we cannot see the 
forest for the trees. 

It is because of this general law, it seems to me, Poetry, in 
that all poetry as it becomes more serious, suppresses, ^ e T e en j ng ' 
in some degree, the sensuous auditory element, appeal to 
Rhyme or recurrent alliteration are felt to obtrude theear - 
themselves and hinder the higher functions of mind, 
as do also too obvious metrical effects. Children's 
verses can stand all this ; it is suited to the lyric 
temper. But in general the more thoughtful, — the 
more spiritual, — the mood, the less it can tolerate of 
mere sensation. It is true there are troublesome 
exceptions, like the terza rima of Dante. But it is 
perhaps more characteristic that Shakespeare neg- 
lected his rhymed couplets as he grew older; while 
in the poetry of Job and of the Psalms the more 
prominent feature is neither rhyme nor measure, but 
rather a stately form, imperceptible to the senses — 
an antithesis or repetition, with solemn emphasis, of 



256 



Experimental Psychology 



Separation 
of arts so that 
each ele- 
ment may 
get its due. 



Instance of 
the auditory 
arts of 
music and 
poetry. 



the thought itself. If there is any other metrical 
arrangement, it is so obscure that its very existence 
is still in dispute. 

But this does not mean that a purified art will of 
necessity become supersensuous ; there is no indica- 
tion that art as a whole is to grow more austere. So 
far as we can now see, the tendency is rather toward 
a division of labor — toward the development of 
special arts in which the different ways of appreciat- 
ing beauty shall each be recognized without slight : 
some arts in which the sensibly present impressions 
shall be all but eliminated and the enjoyment con- 
nected with the ideas they arouse shall be the chief 
thing; and other arts in which the mental activity 
of interrelating the parts of the composition is subor- 
dinate and the sensory pleasure of the moment can 
come well to the front. Music and poetry are good 
instances of such a development already completed. 
In primitive life, music is not cultivated as of value 
in itself ; it is subordinate to the dance, or it appears 
as undistinguished from poetry — the verses are 
chanted or sung. Music is here but a handmaid of 
other arts. But men finally perceive that it is impos- 
sible to do full justice to all sides at once, and that if 
the ideas of poetry are so excellent as to engross the 
attention, the mind will inevitably neglect the sensu- 
ous clothing of the thought, — the music of the verse ; 
and, on the other hand, the mere musical side can 
satisfy us better if attention is not demanded for other 
things. Think of using Hamlet as the libretto of an 
opera ! The opera is always a compromise ; it gives 
us neither the highest musical nor the highest dramatic 



Color and the Fine Arts 257 

effect 1 For this reason music finally asserts its inde- 
pendence of dancing and poetry, and is cultivated for 
its own sake. The modern development of pure 
instrumental music thus does justice to the sensuous 
side, which poetry has more and more neglected. 
And in such music even an imitation of natural sounds 
or any intellectual constraint is of doubtful propriety. 
Because of this the descriptive pieces of Berlioz do 
violence to one's sense of fitness, and we resent it 
when some one proposes to interpret Beethoven's 
Fifth Symphony as a philosophical tract. 

No such complete differentiation has taken place The visual 
in the visual arts, and it is perhaps doubtful whether haps^nder- 
it ever will occur. And yet there are signs of such a going a like 
movement. We are certainly much more willing to 
separate sculpture from painting and are more satis- 
fied with the colorless form of things than were even 
the Greeks. They often colored their marble build- 
ings and statuary, — a treatment which we should now 
regard as in bad taste. And our strong interest in 
work in black and white is further evidence that 
we can enjoy visual representations from which 
color is entirely excluded. The natural correla- 

1 I must, of course, leave the settlement of Wagner's place in art 
to others. His "music dramas," especially those of the Ring Cycle, do 
not seem to me a refutation of the view here espoused. The music 
in them is unsurpassed as decoration or atmosphere for the great 
dramatic movement; but, judged by itself and apart from this ancillary 
function, it hardly appears to reach the excellence of the best inde- 
pendent music. And while his librettos are probably the best of their 
kind, yet even the partisans of Wagner would hardly wish them to be 
compared, as dramas, with the works of Sophocles or of Shakespeare. 



development. 



2 5 8 



Experimental Psychology 



Non-imita- 
tive color 
has as great 
emotional 
value as mu- 
sical sound. 



tive of this would be an art in which color should 
come to the very front — an independent art in 
which hues should play the same role that tones 
do in music. The nearest approach to this is where 
the colored surface has ceased to be immediately 
imitative, as in certain conventional patterns of mo- 
saic or fresco or weaving. But here the art is one 
of color and spatial design together, and not of color 
alone. And ordinary painting permits even less 
freedom in the use of color. The most radical color- 
ist of the day would never quite dare to lay his pig- 
ment on so that it gave no suggestion of natural 
objects; painting is bound more or less by the laws 
of imitation both as to form and as to color. If an 
artist's color seems extreme and wide of the facts, he 
will usually attempt the defence that at least he him- 
self actually does see such tints in the object. But 
the musician is entirely free from any such restraints ; 
he is never asked to show that natural things give 
forth the tones and harmonies that he presents, and 
that he is merely revealing them to us. Even in the 
well-known passage in Beethoven where Fate, it is 
said, is knocking at the door, how free the artist is to 
present this in tones that it would be impossible to 
think of as due to strokes on wood ! It is given chiefly 
by the strings, and the abstract rhythm and force is 
in fact the only point of resemblance to the object 
the artist may have had in mind. 

The reason why no similarly free use of color has 
been developed does not seem to me to lie in the char- 
acter of color itself. Its splendor and emotional power 



Color and the Fine Arts 259 

is certainly not less than that of sound. And if given 
in proper sequences, with regular variations of inten- 
sity or tone, it is capable of giving us the feeling of 
rhythm that music offers. Sound, then, has no in- 
herent advantage over color ; its earlier attainment 
of an independent position in art is probably due to 
the greater mechanical ease with which it can be 
produced and rapidly modified. If it were mechani- 
cally simpler, nature would have supplied us not with 
a voice, but with some kind of an organ for the emis- 
sion of colored lights in rapid succession. Think of 
the handicap such an organ would have given in 
the struggle for existence ! how it could have been 
used as a kind of search-light for prey, or in commu- 
nicating with distant friends, or to excite admiration 
and love in primitive courtship ! Or if it had been 
possible for man to change the color and intensity of 
fire and make it answer his bidding at the instant, with 
the same ease with which he can strike the strings of 
a harp or change the pitch and volume of sound from 
his simple pipes, the free artistic use of light would 
have been as inevitable as music. It is fast becom- 
ing possible for men to have this perfect control over 
brilliant colors, and it seems to me probable that in 
the distant future, when the unbeautiful associations 
of carbons and dynamos and insulated wires shall have 
passed away, and all these things shall be thought of 
as having existed from an immemorial past, pure its artistic 
color in harmonious combinations, passing in stately P osslblllties 
and rhythmic cadence through the gamut of bright- 
ness and of hue, and the whole worked out with be- 



260 Experimental Psychology 

ginning and climax and close — all this may not seem 
unfit to be used as a means of aesthetic expression. 1 
That a display of color itself, apart from any inherent 
imitative meaning in its arrangement, is capable of 
producing noble effects is shown by the feeling with 
which men have always watched the spectacle of the 
sunset. 
Conclusion. But art is long, and if one were to keep merely to 
the psychology of it, he would be led on and on. The 
enjoyment we take in imitation has had but a passing 
sentence ; the pleasure we find in expressing our- 
selves ; the absolute need there is of giving expression 
to our nature ; the reasons why art and play are so 
refreshing, — all these have not had a word. We 
have only noted some few things that lay within and 
near the borders of the experimental work. As I 
said at the beginning of the preceding chapter, the 
experiments confessedly deal with but the rudiments 
of the artistic impulse. There is perhaps no need of 
an apology because they do not usher in the whole 
philosophic truth. They have brought us a little 
nearer to a complete natural history of art. It is 
easier through them to see the varied features of 
beauty, and to mark how its many minute details con- 

1 An elaborate system of this kind has recently been proposed by 
Favre, La musique de couleurs, Paris, 1900. He points out how differ- 
ent a true art of abstract color would be from the mere " play" of our 
electric fountains. According to the account in the Revue Philoso- 
phique, January, 1901, he proposes "scales" and "keys" of color. I 
cannot find, however, that he has thought of the great possibilities 
involved in the careful application of rhythm. The opportunities for 
its use in a color succession are even greater than in the case of suc- 
cessive sounds. 



Color and the Fine Arts 261 

tribute to the total effect. If they assist us also to 
understand something of the reasons for personal 
preference and for the historical growth and separa- 
tion of the arts, they may be accounted at least the 
beginning of an excellent work. 



CHAPTER XIV 



THE CONNECTION OF MIND AND BODY 



The distinc- 
tion of mind 
and body. 



Problem of 
their union. 



The distinction between mind and body, spirit and 
matter, is a comparatively late achievement. In the 
youth of the world, men were neither materialists nor 
spiritualists. For them, physical processes were in- 
fused with spirit, while spirit itself was a kind of 
material thing. So that consciousness could be re- 
garded as on the same plane with purely physical 
processes, like digestion or breathing. Homer, for 
instance, does not hesitate to say that Hephaestus, 
the clever mechanic-god, made golden handmaids 
that not only moved about, but had " intelligence in 
their hearts" and "skill of the immortal gods." 1 
Thinking was evidently here conceived as something 
that a well-contrived machine could do. With a 
deeper hold on life, however, men begin to distin- 
guish between the things of the flesh and those of 
the spirit ; mind and body stand out in strong con- 
trast, and it then becomes a question what the con- 
nection of the two may be. 

Like every study that comes close to the moral and 
religious interests of men, this has had its prejudices 



1 Iliad, Bk. XVIII, 11. 417 et segq., especially: — 

T17S kv (ikv v6os ecrrl fxera <f>peaiv, ev 5e kclI avdrf 

Kal aQtvos, adavaruv 5t 8eQi> airo 6/070 taacrtv. 

262 



The Connection of Mind and Body 263 

to overcome. One party has been so sure of the 
things of the body and of natural law, that the thought 
of activities immaterial savored to them of superstition 
and nescience. On the other hand, those who felt so 
keenly the reality and supreme demands of the spirit- 
ual life could not tolerate the thought of its essential 
connection with the body ; between corruption and 
the incorruptible there could be no bond. 

The result of the present-day physiological psychol- Trend of 
ogy favor neither side ; or perhaps we may more ^^^f 103, 
truly say it favors and opposes both. So the trend 
of the present chapter will be to propose a via media, 
with all the advantages and disappointments which 
compromise and halfway statements always bring. 

In two different directions there have been impor- 1. The phys- 
tant additions to our knowledge of the connection of sion^men- 
mind and body. It had always been apparent that tai states, 
the mind influenced the body : that we could will to 
move our hand or foot, and the body obeyed our inner 
command ; that different emotions had their charac- 
teristic bodily effects, — the clenched fist, the con- 
tracted brow, the set jaw of anger, the smile of 
pleasure, and so on. And in the chapter on " Imita- 
tion and Suggestion " it was shown that, even without 
any perceptible emotion or act of will, the mere 
idea or suggestion of an action when once it lodges in 
the mind tends to flow out through our nerves and 
muscles into the very act itself. We cannot see 
another's movement without in some degree, as it 
were hypnotically, imitating his act. 

But it remained for modern psychology to show 



264 



ExperimentaJ Psychology 



The subtlety 
of these 
organic re- 
sponses. 



Apparatus 
used. 



Character of 
the records. 



that in even subtler ways than these the mental state 
is reflected in the condition of the body. It is now- 
known that imperceptible changes of the inner or- 
gans follow every shade of variation of the psychic 
life. The most important of these physiological 
alterations are found by examining the distribution 
and pressure of the blood under different psychologi- 
cal conditions — an examination which has been made 
possible by some clever recording devices, delicate, 
yet in mechanism simple enough. The apparatus for 
recording the pulse is called the sphygmograph, one 
form of which is shown in Fig. 55. But by a still 
better contrivance called the plethysmograph or (save 
the mark!) sphygmoplethysmograph (Fig. 56) we get 
not only the pulse, but the changes in the general 
volume of a limb. The principle here applied is as 
old as Archimedes — that if anything is immersed in 
water, the level of the water will rise according to 
the volume of the object we put into it. If we en- 
close the forearm, for instance, within a glass cylin- 
der, and, through a small opening at the top, like 
the neck of a bottle, pour in tepid water until the 
cylinder is full, the height of the water in this open- 
ing is found to vary from time to time, according to 
the mental state of the person whose arm is in the 
vessel ; and, by means of a simple pneumatic contri- 
vance, these changes of the water's level can be made 
to write their own record on a sheet of moving paper. 
In this way we get a somewhat complicated line, 
every rise of which denotes that the arm at that 
moment expanded, while a fall implies that its volume 
diminished. In the accompanying record (Fig. 57) the 








Fig. 55. — Sphygmograph. 




FlG. 56. — Plethysmograph. For recording changes in the volume of the arm, 
that accompany changes in the mental state. 



The Connection of Mind and Body i6$ 

smaller wave-like changes are due to the separate pul- 
sations of the heart which force the blood rhythmically 
into the extremities ; and since the blood-vessels are 
elastic, greater pressure makes them expand, and 
with less pressure they contract. The volume of the 
arm thus changes at every heart-beat. The upper 
curve of this record shows the normal pulse of the 
forearm during mental repose. But, near the begin- 
ning of the second line of the record, at the point 
marked by the arrow, the person who was here experi- 
mented upon was asked to multiply 22 by 14, and it 
is clearly seen that immediately thereafter the form 




Fig. 57. — The upper record is of the normal pulse in the forearm. The 
lower shows effect of mental arithmetic (multiplying 22 X 14). (From 
Mosso.) 

of the individual waves changes so that there is no 
break in the up-stroke, as there was before. But, 
more important still, the general level of the curve 
is different, showing that the volume of the arm for 
a short time increased, and then was steadily reduced. 
Far more striking results can be obtained if we re- 
cord, not the change of volume of some outlying 
member, like the arm, but the alterations of the brain 



266 Experimental Psychology 

Mosso's ex- itself. Mosso, the famous Italian physiologist, experi- 
SiTiiving ° n ment ing on several unfortunates whose brains had 
brain. been laid bare by accident or by necessary surgical 

operation, was able to take tracings of the changes 
of volume of the brain under different mental condi- 
tions. 1 He found that an increase of mental action 
is signalized by a sudden increase in the size of the 
brain, due, no doubt, to the added amount of blood 
which is immediately forced up to it. The accom- 
panying records (Figs. 58, 59, and 60) were taken 
during experiments on an Italian peasant, with an 
arrangement of apparatus in principle like that 
already shown in Fig. 56. 

In the first of these (Fig. 58) we have a simultane- 
ous record from brain and forearm, the upper curve 
of this figure being that of the brain. At the point 
marked by the arrow, the man was required mentally 




Fig. 58. — Simultaneous record of pulse in brain (upper curve) and fore- 
arm (lower curve). At a the subject is required to multiply 8 X 12; at 
to he gives the answer. (From Mosso.) 

to multiply 8 by 12, and at (o he gave the answer. 
It is noticeable how much more marked is the change 
in the brain, at these critical points, than in the fore- 
arm. 

1 Ueber den Kreislauf des Blutes im menschlichen Gehirn, Leipzig, 
1881. Figs. 57-60 are taken, by kind permission, from this work. 



The Connection of Mind and Body 267 

The next record (Fig. 59) was taken while this 
peasant, Bertino, was asleep, and shows the effect 
upon his brain produced by calling his name aloud, 
at the point marked by the arrow, yet without 




Fig. 59. — Record of brain pulse during sleep. At the point marked by 
the arrow, the subject's name is called, without, however, awakening 
him. (From Mosso.) 

awakening him. Not only does the volume of the 
brain change, as shown by the general rise of the 
curve, but the individual waves have a different form, 
having elevations on both sides of the crest, whereas 
before this stimulation the extreme left-hand eleva- 
tion of each was the highest. 




FlG. 60. — Simultaneous record from brain (ist and 3d curves from bottom) 
and forearm (2d and 4th). The lower two curves are during repose; 
the upper two during strong emotion. (From Mosso.) 

The record in Fig. 60 was taken during an ex- 
periment that was in progress at midday. The curve 



268 Experimental Psychology 

at the very bottom shows the pulsations of the brain 
while the man was at perfect ease, the curve just 
above it being the simultaneous record from the fore- 
arm. Later on, he was upbraided for some slight move- 
ment which disturbed the experiment, and became 
excited and chagrined. The third and fourth curves 
from the bottom are a simultaneous record from 
brain and forearm, respectively, taken at this time ; 
the waves of the brain-curve are wild and high, as 
compared with those taken earlier. Now, at the point 
in this third line marked by the arrow, the neighbor- 
ing church-bell struck the hour of twelve ; the curve 
suddenly leaps to a still greater height. Mosso found 
later that the peasant was accustomed to cross him- 
self at noon, and say his Ave Maria, and his feeling 
of embarrassment at not being able to perform his 
simple rite is doubtless the reason why the stroke of 
the hour made such a sudden and marked change in 
a record already showing excitement enough. 

The meaning The result of all this, and of much more of the same 
kind, 1 is to bring about the conviction that body and 
mind are in most intimate connection, and that the 
intercourse of the two is not occasional, but is con- 
stant. Formerly we believed that some strong emo- 
tional excitement, or a definite act of will, must be 
present if there was to be any manifest expression of 
the mental state. But it is now generally accepted 

1 Considerable work has been Jone, for example, in noting the 
connection between pleasure-pain and the form of the vascular and 
respiratory tracings. The latest of such studies is that of Zoneff and 
Meumann, Philosophische Studien, Vol. XVIII, p. I. 



of these 
experiments. 



The Connection of Mind and Body 269 

that the body reflects every shade of psychic opera- 
tion ; that in all manner of mental action there is some 
physical expression. " All consciousness is motor " 
is the brief statement of this important truth; every 
mental state somehow runs over into a corresponding 
bodily state. 

Innocent as all this may seem, it has in reality They revoiu. 
revolutionized our view of expression, and of its in flu- ^ew^^ex- 
ence upon mental states. We used to suppose that pression." 
the bodily expression of what was going on in the 
mind was of no great importance as far as the mind 
was concerned ; that in the case of fear, for instance, 
there would still be fear even if there were no palpi- 
tation of the heart, no pallor, nothing of what old 
y£neas felt when (as he says) — 

Obstipui, steteruntque comes et vox faucibus hcesit. 

But we now know better ; we know that this outward 
physical expression, as we call it, is a most important 
thing ; it makes the fear real. The feeling of what 
is occurring in our veins and muscles rolls back upon 
the mind and gives the mental state definiteness and 
"body." Without the physical concomitants and the 
feelings they arouse, the mental process would be 
pale and shadowy. Half the fun of a joke, therefore, 
is in the laughter ; half the sadness of sorrow comes 
from an actual depression of body — a weight of 
physical distress. 

It is not true, then, that there first exists a mental The mental 
state in full vigor, which later operates upon the g^es"^" 5 
physical world. On the contrary, what goes on in are one and 
our minds never is really there until it is expressed. lnsepara 



270 Experimental Psychology- 

Externalizing an idea in some way, putting it off 
from us, so that it may return upon us as from 
without, is the only way to gain possession of it our- 
selves. We must try to articulate the thought, speak 
it to some one, put it into practical use, or it fails to 
take form. Modern physiological psychology thus 
points out that there is an essential connection be- 
tween body and spirit, and is opposed to the older 
doctrine that the two are in antagonism, that the 
body and the sense-world are opposed to the moral 
life, — a doctrine that, developed in Plato, found ex- 
pression in asceticism and the life of the hermit and 
the anchorite, — a life of pure contemplation, of mor- 
tification of the flesh, as opposed to physical activity 
and health. Such a doctrine is unpsychological. 
The body is not a clog upon the mind ; it is not 
" a muddy vesture of decay " that hems us in. It 
is an indispensable factor in the highest develop- 
Characterof ment both of intellect and of character. A really 
bo^iecTspirit disembodied spirit (the ghost believed in popu- 
larly is never quite disembodied, but always retains 
some tenuous shape), a spirit absolutely without 
a body, would, so far as we can now see, have no 
point of contact with a sensible world, no oppor- 
tunity of giving sensible expression to its incipient 
mental processes. These processes would have no 
physical reverberation, and, lacking the quality by 
which alone they could become real to others, they 
would soon cease to be real to the person himself. 
This, I imagine, is the scientific basis for the old 
truth that " faith without works " is vain. A men- 
tal state that does not come to some characteristic 



The Connection of Mind and Body 271 

outward expression is only a half-real mental state 
at best. 

But we must pass to another field of investigation 11. The seat 
which has to do with the topic before us, — the in- ° n \^ e jjjjj} 
vestigation of the seat of consciousness. Brought 
up, as we are, in the belief that the brain is the 
chief organ of the mind, it seems as if each of us had 
some direct knowledge that thinking takes place in 
the head. But history shows that the unsophisticated 
man is ready to localize his mental processes almost 
anywhere but in his brain — in his heart (as Aristotle 
did) or elsewhere. One may recall the expression, 
"my reins instruct me in the night season." 1 But 
having found that the brain is, in some peculiar sense, 
the organ of the mind, the further problem arises, 
whether the mind has connection with all parts of 
the brain equally, or whether there is a still more 
definite seat of the soul. The older metaphysical 
definition of the soul — that it is a simple substance, 
and, because it is simple, necessarily without exten- 
sion — led men at first to maintain that it could be 
present only at some single mathematical point in the 
brain. Now the brain is, in most of its structure, a 
double organ : there are the two halves of the cere- 
brum, separated by a deep fissure ; there are two 
optic thalami, two corpora striata, and so on. But 
at one unique place, well covered under the mass 
of the hemispheres, and at a kind of geographical The pineal 
centre of things, there is a small body called the gland " 
pineal gland, which has not the double structure so 

1 Psalm xvi. 7. 



272 



Experimental Psychology 



The ventri- 
cles of the 
brain. 



Phrenology 
and the 
cerebral con- 
volutions. 



common in the other parts. Its smallness, — a very 
small pea is about its size, — its singleness, its central 
position, made it seem the fit habitat of the spaceless 
mind ; and here Descartes supposed the soul had its 
seat, governing the body from this point of vantage, 
playing upon its stops, much as an organist at the 
keyboard controls his instrument. But later it seemed 
more suitable to think of the soul as in less gross sur- 
roundings ; so its abiding place was changed to the 
fluid in certain cavities of the cerebrum known as the 
ventricles ; here it would not be actually embedded 
in the nervous substance ; it would govern the body 
through the brain, and yet without such immediate 
material contact. Thus did men, in their theory, 
guard the spirit from contamination. 

Strange to say, it was Gall and the phrenologists 
who drew attention away from these curious specula- 
tions and emphasized the physiological importance of 
the convolutions, — the outer surface of the hemi- 
spheres, — teaching at the same time that different 
portions of the surface were given over to different 
spiritual functions : acquisitiveness, combativeness, rev- 
erence, and the like. This notion, that the nervous 
counterparts of the various mental functions are 
scattered about in the brain, was at first strenu- 
ously opposed, and much was made of such evidence 
as that afforded by the celebrated crow-bar case, where 
an enormous wound in the brain resulted in no per- 
manent mental trouble whatever. And, indeed, there 
was no very good support for this doctrine of scat- 
tered localization until about the year 1863, when 
Broca made the interesting and important discovery 



MOTOR-TACTUAL REGION 



VISUAL REGION 




v AUDITORY REGION 

Fig. 6i. — Diagram of the outer surface of the right hemisphere of the brain. 
The dotted areas represent the visual, auditory, and motor-tactual " cen- 
tres," respectively. (After Flechsig.) 



MOTOR-TACTUAL REGION 






VISUAL REGION p???V& : -*-*/;^ 




OLFACTORY REGION 



Fig. 62. — Diagram of mesial surface of the left hemisphere of the brain. The 
dotted areas represent, respectively, the visual, motor-tactual, and olfactory 
" centres." (After Flechsig.) 



The Connection of Mind and Body 273 

that if the third frontal convolution of the left side, Broca's 
in right-handed persons, was disordered (the region dlscover y- 
to which phrenologists ascribe " constructiveness "), 
speech became a hopeless tangle of sounds — a dis- 
ease now known as aphasia. This was really the 
first of the great modern discoveries in brain-localiza- 
tion. The work was thereafter carried on, partly by The later 
experiment on living animals, by laying bare the ™ ork ° n 
brain and electrically stimulating it at different points, zation. 
or by carefully removing portions of the nervous 
matter and noting any change in the animal's beha- 
vior. But the work has been marvellously aided by 
the use of chemical stains which have the power of 
bringing out the inner structure of the brain. This 
post-mortem staining and the careful examination of 
the effects of local brain-disease have been the main 
reliance in learning what parts of the human brain 
are of most importance for the mind. 

The result of all this study has been to show that, The motor 
in the first place, there is a wide zone, — beginning zone " 
near the centre of the top of the head (the seat of 
"veneration," according to the phrenologists) and 
running downward and forward, — which has to do 
chiefly with the conscious control of the muscles. It 
is, for this reason, usually called the " motor " zone, 
although in all probability it is quite as much a re- 
gion for the sense of touch and for all those feel- 
ings which come to us from our muscles and skin 
(Figs. 61 and 62). Even the brain-connections of spe- 
cial groups of muscles with this region are now pretty 
accurately known ; so that the brain-surgeon, once he 
is certain that this surface of the brain is affected, 



274 



Experimental Psychology 



Sensory 
centres. 



Cautions 
as to these 
results. 



can tell with considerable security what particular 
portion of it is diseased, according as there is, say, 
paralysis of the right leg, or of the left hand, or of 
the muscles involved in speech. Besides this motor 
region, or, as we might just as well call it, the zone of 
organic sensations, 1 special regions have been dis- 
covered for sight, hearing, and smell. The region 
for smell, as we might expect, is found to be located 
at the lower inner surfaces of the cerebrum that lie 
not far from the upper wall of the nasal cavity. The 
nervous centre for hearing lies on either side of the 
brain in what is called the region of Wernicke, — after 
its discoverer, — the place to which " secretiveness " 
had been attributed. And, finally, in defiance of all 
common-sense, the centre for sight lies in the very 
back of the head. Laura Bridgman's brain, for in- 
stance, showed a marked thinning out of the cortex 
of this rear region of the brain ; it had not been used 
from early childhood, and had remained undeveloped. 2 
On the basis of these discoveries, one is tempted 
to say that the function of sight, for instance, is lo- 
cated in the posterior region of the brain. But this 
is only a careless half-truth. Probably all that we 
should be conscious of, if this region alone were 
active, would be the naked light impressions stripped 
of all association and, therefore, without connection 
and significance. For sight is much more than light 



1 Flechsig (following Munk), Gehirn und Seek, Leipzig, 1896, 
p. 62. Figs. 61-65 are taken, by kind permission, from this work. 

2 Donaldson, " The Extent of the Visual Area of the Cortex in Man, 
as deduced from the Study of Laura Bridgman's Brain," American 
Journal of Psychology, Vol. IV, p. 503. 



The Connection of Mind and Body 275 

and color ; we must be able to make out what these 
signify ; we must be able to translate them into 
tactual, auditory, or olfactory terms. We really see 
things with practically our whole brain, and not alone 
with what we call the visual centre. If a convolution 
of the brain cannot cooperate with other convolutions, 
it is as good as lost. Thus in a patient of whom we 
have a report by Heubner, disease partially discon- 
nected the auditory region from the other parts of the 
brain-surface ; under these circumstances the person, 
it is true, could repeat mechanically any words dic- 
tated to him, — he thus retained his sense of sound, 

— but he was absolutely unable to know what the 
sounds meant. For any very important function, 
then, the various parts of the brain act as a whole, 
and the phrenologists' notion is absurd that we imag- 
ine with one isolated portion of the brain, and recol- 
lect with another, and pass judgment with still a third. 
In the adult brain, at least, well-nigh all parts of the 
brain together take a hand in any significant action. 

Recent discoveries show that this is far less the Peculiarities 
case in the infant's brain. The development soon J^V 5 inants 
after birth shows that the different parts of the gray 
surface grow up in comparative separation. The very 
earliest to develop are the centres of touch and smell 

— the functions which the animal uses most ; so that 
the babe is at first on this animal plane, where smell 
and touch are the chief avenues of the mind. The 
next to appear is the sense of sight ; and last of all 
comes the sense of hearing. 

Quite as interesting as this serial development of 
the different senses is the fact that these different 



276 Experimental Psychology 

regions — of touch, smell, hearing, and sight — have 
at first no apparent nervous connections with one 
another. Not until almost the third month after birth 
are there the rudiments of fibres uniting these various 
sensory tracts. 1 This, of course, means that none of 
those conscious associations is as yet possible between 
one sense and another, which adults have when the 
sight, for instance, of heliotrope suggests its perfume, 
or when the sound of a person's voice recalls his face. 
It is difficult for us to conceive in what a disjointed 
condition the child's consciousness must be before this 
time, — sights that suggest no sounds, touches that 
arouse no thought of taste or smell, each item, as it 
appears in the mind, being blankly received for just 
what it is, pointing to nothing beyond itself, and, for 
this reason, being as nearly without form and void as 
anything in the mental life can be and still be mental. 

The value of With this all too brief account of these discoveries 
foroursSdy * must leave the concrete, experimental part of the 
subject. But the importance of such facts as these 
for the natural history of the mind seems to me so 
evident that I cannot at all agree with a recent writer 
of high standing in psychology who has soberly urged 
that the physiologists cannot help us in the study of 
psychic phenomena — that physiology is constantly 
aided by psychology, but is of necessity unable to give 
anything in return. On the contrary, these studies 
of the nervous system offer a means of discovering 
purely psychological facts that we can unearth in no 
other way. How otherwise than by a physiological 

1 Flechsig, op. cit., p. 106. 




Fig. 63. — Section of infant's brain, one month after birth (stained). The 
relatively advanced development of the lower centres is shown by their 
taking a strong stain. (After Flechsig.) 




#*^ VISUAL CONNECTON 



AUDITORYCONNECTON 



Fig. 64. — Stained section of infant's brain at beginning of second week after 
birth. The relative backwardness of hearing, as compared with sight, is 
shown by the faintness of the auditory connection as compared with the 
visual. (After Flechsig.) 




Fig. 65. — Stained section of infant's brain about five months after birth. 
Showing the advance in the development of the higher centres, as com- 
pared with Fig. 63. (After Flechsig.) 



The Connection of Mind and Body 277 

investigation could we yet have said, for instance, in 
what order the infant's consciousness of sense-im- 
pressions arrives or when the interconnections among 
them are built up ? The value of the physiological 
work the psychologist must cordially acknowledge. 
And while it is true that the brain is not the mind, 
and that, in order to translate brain-discoveries into 
psychological discoveries, some knowledge of the 
purely mental realm is necessary, yet it would seem 
highly ungracious to withhold our appreciation for 
that reason and stiffly to insist on the exclusive worth 
of the introspective method. The value of the intro- 
spective method is sufficiently patent to free us from 
the need of proclaiming it both in season and out of 
season. 

But on deeper grounds than these there is apt to what is the 
be a clash between the students of mind and those of tru ^ relation 

01 brain 

the brain. The physiologists often give the impres- and mind? 
sion that, in their view, the brain-process is the only 
real process there is, and that mental phenomena are 
but a special way of regarding the action of the brain. 
Or if they do distinguish the nervous from the psychic 
act, the psychic is considered as a mere effect or ex- 
pression of the activity of the brain. Now when we 
speak of cause and effect, we almost invariably imply 
that the cause is a much nobler and more significant 
thing than its effect. All of us, for instance, would 
prefer to be causes in the world rather than effects. 
So that when the brain-specialist announces that he 
has discovered in the gray cerebral matter the cause 
of mental operation, the lover of mind naturally re- 
sents this as a degradation of the object of his affec- 



278 



Experimental Psychology 



tion. If either is to be cause, he feels that this office 
should fall to the mind ; the mind is the very kernel 
of personality, the saat of morals and intelligence, 
and must never be regarded as subject to the beck 
and call of matter. 



The more 
prominent 
theories : 
interaction 
and parallel- 
ism. 



We have, then, a number of doctrines in glaring 
opposition. In the first place, there is the view that 
the brain either is the mind or at least regulates the 
mind ; and, over against this, is the conviction that 
the mind is superior to the brain and operates it. But 
this extreme opposition is usually softened so that 
now one side and now the other has the upper hand — 
the doctrine of interaction between mind and brain. 
Finally, there is another compromise theory that 
has a large and influential following at the present 
day, — a theory persisting from the times of Geulinx, 
Spinoza, and Leibnitz, that neither the brain controls 
the mind nor does the mind control the brain, but that 
they run in essential independence, side by side, like 
two clocks, both telling in their own way a consistent 
story, and yet neither of them exerting any influence 
upon its companion. This is the doctrine of parallel- 
ism. According to parallelism, there is no real inter- 
action between mind and brain ; the mind does not 
control the brain ; neither does the brain, the mind ; 
they are simply in harmony. 1 



1 For brevity's sake I have taken what is historically the main cur- 
rent of parallelism. But the prestige of the word has led many to call 
themselves parallelists, whose views in regard to the relation of brain 
and mind are most divergent. 

It seems to me that if the term "parallelism" is to have any 



The Connection of Mind and Body 279 

We cannot here review the strong evidences which Reflex action 
each of these views presents. Only a single illustra- J^S Pafal " 
tion in regard to parallelism can be presented. The 
facts of reflex action, — for instance, that a frog 
deprived of its cerebrum will croak, and swim, and 
perform other complicated actions under circum- 
stances that preclude the thought that its mind is 
controlling its members, — such facts as these have 
led many to believe that all bodily acts are essentially 
of this reflex type. If the body is capable of doing 
so much without mental guidance, as reflex action 
shows, why not suppose that the body, of itself, with- 
out help from the mind, is capable of all ? And if 
it can perform its many functions without mental aid, 
there seems even less difficulty in the other half of 
the theory that the mind performs its acts without 
aid from the body. According to parallelism, then, 
it is an illusion to believe that the mind controls the 
body. The body is an automaton, haunted by a 
mind, and the experiences of the mind correspond to 
the doings of its automaton body, and some of the 
doings of the body correspond to acts of its indwell- 
ing mind. But there is no real cause-and-effect relation 
between these two classes of acts. The bodily acts 
are caused solely by other physical acts ; the mental 
events are caused solely by other mental events. 

definite meaning at all, it should imply, as it has, in the main, histori- 
cally : — 

(1) That every mental process has a fixed cerebral process regularly 
accompanying it temporally (and not just "logically"), and 

(2) That there is no causal connection between the corresponding 
mental and cerebral processes. 



I 



280 



Experimental Psychology 



But sense- 



On first hearing a theory like this, one is apt to 
hardTcf 011 iS feel that there are P lent Y of known facts to disprove 



reconcile 
with this 
view. 



it. But such is not the case. Almost everything that 
we know about the mind and body could, perhaps, in 
an extremity, find a place within this view. At the 
same time there is a class of facts that require some 
torturing to make them submissive to the theory, 
particularly the facts of sensation and perception. 
Sense-perception is the crux of parallelism and will 
some day, I fear, be its death. The experience of 
seeing a bright light or of hearing a loud sound is 
quite as truly a mental occurrence as is a conception 
or a train of reasoning, and according to parallelistic 
principles must be explained by its mental antece- 
dents without calling in any physical influence what- 
ever. When you are startled from a revery by some 
crash in the street, caused, let us say, by a falling 
sign, your sudden mental impression (this theory has 
to assume) is not caused by the physical disturbance 
without, but by some mental processes essentially 
disconnected with the outer world. While physical 
nature has been rusting away the fastenings and 
stirring the wind that brings down the sign, the inner 
processes of your own mind, and of the minds of 
every one else in the neighborhood who hears the 
noise, have been silently preparing to call forth 
sound-sensations of similar loudness and jangle in 
the various persons, just in the nick of time when 
the sign falls and the air-waves cause the ner- 
vous disturbances that dart inward to the brain- 
cortex. When one remembers that not a shred of 
evidence exists of any antecedent mental processes 



The Connection of Mind and Body 281 

that might cause the sensations of noise (or of any other 
similarly unexpected irrupting impression), he begins 
to appreciate something of the enormity of this 
theory. It separates on purely a priori grounds phe- 
nomena that empirically have every evidence of causal 
connection. It thus leaves the world of experience 
in a disjointed condition that natural science will, as 
time goes on, be less and less inclined to tolerate. 

But for still other reasons it seems probable that Parallelism 
parallelism will in the end die of neglect. For ^ottfon^ 
the influence of evolution is directly against it. The 
machinery by which evolution moves is such that 
every important and wide-reaching fact in the world 
holds its place there only because it is of service. 
Every significant and persistent strain in human 
or in animal life can be accounted for only on the 
supposition that it is of use in maintaining the crea- 
ture or its species upon the earth, and because of its 
use it has been encouraged by selection. 

Now parallelism is in conflict with this biological 
principle of utility. For, if the mind only seems to 
influence the body, while in reality all physical acts 
spring solely from physical causes, then there is no 
accounting biologically for the presence and persist- 
ence of a reasonable and practical and social mind, 
such as accompanies the bodies of most men, as well 
as of some animals. It becomes at best a mere 
by-product or casual accompaniment of processes 
that are biologically significant. If parallelism were 
true, an entire absence of the mental stream, or 
the presence of a consciousness which took no in- 
terest in the welfare of the body, would have been no 



282 Experimental Psychology- 

handicap whatever. A mind that preferred cold 
and hunger and pain and unsocial ways would, 
physically speaking, be at no disadvantage if only 
its body preferred warmth and food and good 
society. Persons with well-adapted bodies, but with 
ill-adapted minds, could then flourish without let 
or hindrance. There would be no path by which 
natural selection could head off and destroy such 
monstrosities, and consequently their kind, which in 
the numberless chance variations would be sure to 
occur, would be as likely to survive as any other. 
As far as biology is concerned, parallelism is con- 
sequently, as Mr. F. H. Bradley has said, a doctrine 
of the uselessness of the soul. 1 And in the same 
way it is, psychologically speaking, a doctrine of the 
uselessness of the body. If all the efficient causes of 
experience are to be found in the mind alone, as 
parallelism maintains, then the body is a useless 
companion of the spirit, and has no essential place in 
its history. 

The doctrine of parallelism, therefore, is bound to 
pass away, not only because we can point to definite 
facts, like sensation, that can be brought within it 
only by violence, but also because it is not in keeping 
with the principles of evolution and with the even 
broader principle that the various facts of experience 
cannot be kept insulated from one another. It runs 
counter to the general trend of our modern thought, 
and for this reason it is at a hopeless disadvantage in 
the struggle for acceptance. 

1 " On the Supposed Uselessness of the Soul," Mind, N. S., Vol. IV, 
p. 176 ; cf. also the fifth chapter of James's Principles of Psychology. 



The Connection of Mind and Body 283 

What, then, is the standing of the alternative notion, The theory of 
that mind and body really influence each other? mteraction - 
What are the difficulties in such a view, and wherein 
is its strength ? 

The main trouble is that mind and body seem to be so The two 
absolutely heterogeneous that it is difficult to see how Sldes seem 

J ° utterly hete- 

one can act upon the other. It is much as if we were rogeneous. 
to attempt to boil water with the theory of probabilities. 
The terms which we try to unite stare vacantly at each 
other, and cannot be brought into any manner of in- 
tercourse. It seems reasonable that matter should 
influence matter, or mind, mind ; but that conscious- 
ness, which is immaterial and unextended, should pro- 
duce changes in the brain, which has entirely different 
attributes, — this has been felt by many to be at vari- 
ance with the principles of modern science. 

It is at variance, in the first place, many think, with Causal con- 
the ordinary conception of cause and effect. For if ggems to im- 
two things — an action of the brain and its corre- piyquanti- 
sponding mental process — are to stand in a causal equality, 
relation, is it not necessary that they should be some- 
how comparable in quantity ? Is it not always as- 
sumed that the effect has a certain quantitative 
relation to the cause, and that what the cause loses 
the effect gains ? But how can we ever say how many 
units of physical energy are the equivalent of a mental 
desire or resolve ? The two lie in different spheres, 
are incomparable, and consequently (it is held) the 
one cannot produce the other. 

The force of this objection is somewhat broken by Weakness of 
a number of reasons. In the first place there is * hls oh i ec ~ 

r tion. 

nothing sacred and inviolable in the prevalent form 



284 



Experimental Psychology 



The idea of 
tause. 



Quantitative 
correlation is 
not impos- 
sible. 



which the conception of cause has taken on. That 
there should be a quantitative equation between cause 
and effect is not one of those truths that are axio- 
matic ; it has simply come about as a helpful device for 
dealing with phenomena in the physical world and of 
getting shorthand formulas (to use Mr. Karl Pearson's 
term) for expressing them. But what serves well 
when we confine our investigations to the physical 
world may not prove most useful when we try to 
cover the larger field that includes both physical and 
mental things. The successful description of this 
larger realm may require us to modify our notion of 
the causal connection, so that quantitative equivalence 
shall be less strongly insisted on. If, for instance, 
the definite evidence both that the mind is efficacious 
in the physical world and that nervous states influence 
the mind — if this evidence continues to accumu- 
late at the rate that it has in the last decade, we 
may well be forced to give up our unnatural paral- 
lelistic way of describing the relation here, frankly 
admit a cross-causal connection between mind and 
body, and rearrange our notion of causality so as to 
fit the mass of empirical facts. 

In the second place, if quantitative equivalence is, 
however, to be regarded as indispensable to a causal 
connection, it is not impossible that this requirement 
may be met. A quantitative treatment of mental 
phenomena does not, to many, appear an utter absurd- 
ity. The preceding chapters, especially the one on 
" The Possibility of Mental Measurements," have 
given what seem to me the indications that it is not 
only theoretically possible to deal with certain aspects 



The Connection of Mind and Body 285 

of mind quantitatively, but that there has been con- 
siderable practical success in doing this. And while 
it may not be feasible to say beforehand how much 
nervous energy is the equivalent of any given mental 
fact, and only experiment can determine this, yet 
the same is true when we keep to the physical 
world. The mechanical equivalent of a given quan- 
tum of heat has to be found by experiment, and 
could never have been argued out a priori. The 
quantitative correlation is, in the first instance, " em- 
pirical," and a causal connection is felt to exist long 
before there is any assurance of these exacter mathe- 
matical relations. The chief evidence of a causal con- 
nection between heat and mechanical motion is the 
frequent occurrence of one with the other, and the 
variation of one as the other varies. Only later, and 
as an extra refinement, is it presumed that the energy 
in the two cases is at bottom identical and to be 
measured possibly by some identical unit. Now as 
to the cerebral and mental processes that would stand 
in a causal relation, the evidence is increasingly 
strong not only that they frequently occur together, 
but that they concomitantly vary in quantity. In the 
case of sensation and stimulation, to take by no means 
the only example, there is found a rough quantitative 
correspondence between the two terms, even though 
the more exact nature of that correspondence be 
variously judged according to the special way in 
which we interpret Weber's Law. 

And as a final (though, perhaps, a less cogent) Difficulty 
reason for not giving too much weight to this ob- e J' en . inthc 
jection based upon quantity, it might be urged that an realm. 



286 Experimental Psychology- 

exact equivalence between cause and effect does not 
seem to be always verified even in the physical world. 
Ostwald, the distinguished German chemist, has 
recently referred to certain substances that by their 
mere presence, without any discoverable loss on their 
part, assist other substances to produce a chemical 
reaction. For instance, if finely divided platinum be 
introduced among certain gases, the latter will com- 
bine much more rapidly than if the platinum were not 
there, and yet the platinum, although it has thus been 
effective in bringing about the combination of these 
other substances, is in exactly the same state after it 
has produced this effect as before. 1 In such instances 
as this the cause does not appear to have surrendered 
a certain quantity of its own being to have it reappear 
in equal amount in its result. No equation between 
them is possible. These and similar phenomena 
may force us, more and more, to the view that by 
cause we mean simply the total set of circumstances 
under which any event regularly occurs. Whatever 
is indispensable for the occurrence of any event we 
must number among its causes, whether the various 
items be of the same nature or not, or whether the 
quantum of one process alters in proportion to the 
Hume's view event which issues from it. Under this view, which 
of cause. j g at "bottom the one which Hume long ago made us 
familiar with, there is nothing absurd in believing that 
mental events are, on occasion, to be numbered among 
the causes of physical acts, and vice versa. 

1 Ostwald, " Chemische Theorie der Willensfreiheit," V erhandlungen 
der koniglich-s'dchsischen Gesellschaft zu Leipzig, Math.-Phys. Classe, 
Vol. XLVI, p. 334. 



The Connection of Mind and Body 287 

But to say that mind is a cause of physical events No bodily 
does not mean that an act of our body ever occurs physiological 
solely by act of the mind and without suitable antecedents, 
physical antecedents. Every one must admit that 
for many occurrences, like that of reflex action, 
the physical antecedents are everything. For other 
acts, like those of will, this doctrine of mental causa- 
tion in the physical world would mean that, how- 
ever many physical antecedents you may discover, — 
heredity, or disease, or habit, or physical excite- 
ments of the moment, — these do not fully explain 
the act. The mind, as well as the body, has con- Yet the mind 
tributed its share to form the total situation out of contributes 
which the action springs. Consciousness might here 
be compared to the scene which impresses itself upon 
a photographic plate. The scene is not the sufficient 
cause of the photograph ; it is an indispensable fac- 
tor, and so must be numbered among the causes of 
the picture, but the picture depends also upon the 
light, depends upon the lens, upon the plate, and 
the chemicals employed in developing it. So, too, the 
inner act of will cannot be impressed upon the world 
by its own inner force alone; its peculiar efficiency 
requires the cooperation of the brain, the nerves, and 
the muscles, with all their intricate organization, his- 
tory, and inheritance. 

But there is a further objection to the possibility objection 
of an interaction of mind and body that must at least based on the 

J m conservation 

be touched upon. It is, that such interaction would of energy. 
be in conflict with the doctrine of the conservation of 
energy, an objection frequently urged at the present 



288 



Experimental Psychology 



Interaction 
escapes this 
difficulty 



time. It is at bottom very like the one we have just 
considered, — the objection from cause and effect, — 
and yet it differs in not appealing to some a priori 
conception of causality, but to certain generalizations 
of science based upon experiment. The thought here 
is, that if a mere mental desire or volition to raise 
my hand can start a brain-process which finally 
causes my hand to move, this would mean a pro- 
duction of energy in the brain without any compen- 
sating loss of physical energy elsewhere. The sum 
total of energy in the physical universe would thus 
be altered every time we willed to move our body, 
and the present belief that the amount of energy in 
the world is constant would be contradicted. 

Many answers have been given to this objection 
of which I shall select only one, given by the late 
Professor Solomons. 1 For every unit of energy 
appearing at some point in the brain as a result of 
our volition (he urged) there might well be a corre- 
sponding loss at some neighboring point. In other 
words, the fact that the will caused the brain-molecules 
to change their condition need not mean a change in 
the amount of energy in the brain or in the universe. 
The influence of the mind might be, not to add to 
the energy of the brain in any way, but simply to 
redispose it, to change the form of the energy 
already there, to determine which among various 
forms it should take, just as we might determine 
whether a given amount of energy in a piece of 
coal should take the form of light or of heat with- 

1 " The Alleged Proof of Parallelism from the Conservation of 
Energy," Philosophical Review, Vol. VIII, p. 146. 



The Connection of Mind and Body 289 

out our decision making any difference in the sum 
of energy involved. 

The intercourse of mind and body consequently 
need not mean a give-and-take of physical energy, 
nor are we required, in accepting it, to give up the 
great principles of our present-day science. 

Interaction therefore cannot as yet be ruled out and remains 
of court and the decision be given to parallelism be- ^ e ve altema_ 
cause it alone is left. Certainly either of them is at 
present a live alternative, with the future looking 
perhaps more favorable for interaction. But even in 
regard to this there are difficulties, in that we cannot 
understand how the interaction takes place. And 
yet, as Lotze has pointed out, any interaction what- 
ever, even between physical things, is in the end a 
mystery. So that the difficulty in psycho-physical 
causation is not a special and peculiar one. One must 
also admit that it is perhaps premature to say just 
what will be the ultimate solution of the problem under 
discussion. We are still too much in the dark as to the 
details both of physiology and of psychology. If one "Corre- 
has caution ingrained, and wishes to avoid even a pro- f^Ufe 5 " 06 
visional decision where the evidence is so far from cautious, 
being all in, it might therefore seem advisable to hold 
to some non-committal doctrine to be called, perhaps, 
" Correspondence," which includes only what practi- 
cally all psychologists would accept. Such a doctrine 
would simply affirm an intimate connection between 
mental phenomena and the brain-cortex, so that occur- 
rences on the two sides correspond, process for 
process, leaving it an open question what the more 
exact relation between the occurrences might be, 



290 



Experimental Psychology 



whether of interaction or of parallelism, or of some- 
thing perhaps different from both. Most persons, 
however, would chafe at such restraint, and would 
prefer to push on, even at the risk of taking the 
wrong road. 



Philosophy 
and the pres- 
ent question. 



The scientific 
problem vs. 
the meta- 
physical. 



And now a closing doubt as to whether in all this 
long discussion we have not, after all, been merely 
tilting at windmills, and, could we but clear up 
our philosophic vision, the whole question as to the 
relation of mind and body might not seem absurd. 
Could not those who believe that mind and matter 
are essentially one, — the monists, for instance, who 
hold that these two are but different appearances of 
some underlying reality ; as well as the idealists who 
feel that matter is but a projection of the mind, — 
could not those who have this faith turn upon us and 
say that, from their philosophic point of view, the 
problem of parallelism or of interaction ceases to 
exist ; that theirs is the true solution of the difficulty 
because it makes us see that mind and matter are 
essentially one ? 

It is doubtless true that the difficulty as to parallel- 
ism or interaction appears in a somewhat different 
light when viewed from the standpoint of philosophy. 
When mind is taken in its widest sense it is, so far 
as we know, all inclusive ; there is nothing beyond, 
and there would consequently be nothing that could 
be either parallel or interactive with mind. In this 
idealistic view, psychic and physical phenomena are 
seen to be but two sets of occurrences within the 
larger compass of mind. But however satisfying such 



The Connection of Mind and Body 291 

an outcome may be to our philosophical instincts, 
I cannot feel that it really solves the problem with 
which natural science is engaged. Even if Professor 
Ward should be right in saying that the brain is but 
part of " experience as a result of intersubjective inter- 
course," while psychic phenomena are our personal 
and private experience, and that consequently all dual- 
ism between brain and psychic events disappears, yet 
the old problem reappears in a new form. The two 
kinds of "experience" are still distinct, and each has 
its separate occurrences, and we have still to decide 
what the natural-science relation between these differ- 
ent classes of events may be. The fact that they are 
both at bottom " experience," and therefore similar 
in kind and origin, does not decide whether the two 
orders of events, scientifically speaking, interact or 
run in independent courses. It is a simple question 
of fact to be settled in exactly the same way as it 
would be if we did not accept the idealistic view. 
Neither idealism nor any other metaphysical concep- 
tion is, in itself, an answer to this question. As well 
might one claim that every query as to what has 
occurred between Briton and Boer was answered 
when once we were told that the two peoples were 
cousins by blood. 

But the psychological and natural-science problem The really 
which we have been considering is, after all, of far absorbm g 

' questions 

less vital interest than the further question of the 
relative worth and permanence of the mind. The 
questions that were asked of Socrates on that morn- 
ing when he drank the hemlock, are the really 



292 



Experimental Psychology- 



are un- 
touched by 
psycho- 
physiology. 



Yet mind 
is not sub- 
ordinate to 
matter. 



absorbing ones to which the experimental work is 
always leading us, but to which it can of itself give 
no answer. Is the body a mere garment which the 
soul may lay aside ? Or is the mind like the har- 
mony which comes from the lyre — something that 
must of necessity cease when the strings are loosed 
and broken ? 

The studies of this chapter are, as I have said, 
no answer to these deeper problems. The scientific 
results stop short of affirming the supremacy of 
spirit; but they also, quite as truly, stop short of 
asserting the primacy of nerves. The experimental 
evidence shows dependence and superiority on both 
sides. While it is true that drugs and disease can 
change the whole tenor of one's thoughts, it is also 
true that will and belief produce radical results in the 
physical world. The effects of hypnotism and sug- 
gestion as a means of healing illustrate this, not to 
speak of the purely material changes that have been 
brought about by the mental force of such men as 
Caesar or Cromwell. We must not feel, then, that 
the experimental evidence favors exclusively the 
view that mental states are caused by the brain. 
Nor must we misinterpret the fact that, in organic 
evolution, intelligence may be regarded as a varia- 
tion which assists the organism in its struggle for 
existence. The fact that the mind is useful to the 
body does not prove that this is its sole function. 
The carpenter is doubtless of service to his plane 
and saw; he sharpens them and keeps them in re- 
pair. So the mind may be of service to the body, 
and yet the body be but an instrument of the mind 



The Connection of Mind and Body 293 

— something to which the mind ministers, in order 
finally to reap benefits of a purely spiritual kind. 

The practical outcome of all this seems to me to The ex- 
be a certain toleration and sanity in regard to both tremists - 
aspects of the world. In the first place, it leads one 
to be suspicious of theorizers who speak exclusively 
in physical terms. It has become almost fashionable Nerve-ceil 
to translate, not only psychological, but also educa- P eda s°gy- 
tional matters into physiological phrases. Much is 
said nowadays of " central " processes ; and the 
child's schooling is discussed as if its nerves alone 
were being treated. Social reforms are to be brought 
about by suitable foods and proper ventilation ; while 
crime, as well as genius, is described as a kind of 
cerebral disease. Such one-sidedness cannot live 
long when once the facts are understood ; but it is 
half true, and, for that reason, all the more difficult 
to dislodge. 

But we should be equally suspicious of those who The real im- 
are blind to the important place the body has in our o°thebody. 
life. We ought to strike some mean between those 
who see only the physical part, and those who dis- 
regard it. The material and sensuous world is not an 
enemy of the spirit ; it is not the source of evil and 
sin, as the followers of Plato would maintain. Evil 
has its root in mind as deeply as in matter. Viewed 
aright, the body is the great opportunity for the mind ; 
it is its means of expression ; it must be depended 
upon in all cases where we act either for ourselves 
or for others. We must learn to respect it more, 
but to respect it only for what it can do for us in our 
higher aims. We must rid ourselves of the older 



294 Experimental Psychology 

view that the body is a sign of finitude and defect, 
and regard it as a servant of our inner life. In the 
Heaven of Dante each spirit was manifest as a flame 
of fire. Each had its radiant body. It would not 
seem to me strange if, some day, there should be less 
hesitation in regarding embodiment as a universal 
mark of mind — that even the divine mind is like us 
in this respect. But quite apart from such a specu- 
lation, it is certain that we are formed after a divine 
pattern in this, at least, that there must be some 
utterance, or revelation of our acts in the outer world 
if our inner life itself is to be complete. The work 
of the physiologists in showing how each inner state 
has its appropriate and necessary expression in the 
physical world would thus be another support of 
Leibnitz's doctrine, that each of us is a repetition 
of the larger world in miniature. 



CHAPTER XV 

SPIRITUAL IMPLICATIONS OF THE EXPERI- 
MENTAL WORK 

The larger meaning of our psychological experi- 
ments is the special subject of this chapter. And yet 
to some extent this has been the topic of every 
chapter of the book. The distinct purpose has been, 
not alone to recount the particular experiments, with 
their apparatus and results, but to show if possible 
their bearing on life. 

There remain some questions, however, that are Laboratory 
.connected with no special experiments, nor with par- ^ndThe 6ntS 
ticular results, but are rather suggested by the work 
as a whole, by the general experimental attitude 
toward the mind. This attitude has more than once 
aroused a doubt as to whether the mind is quite as 
worthy of respect after it has been subjected to 
machinery and computations. Does not the very 
fact that the mind submits to such treatment imply 
that it is on a lower plane, that it is grosser, than we 
may have once believed ? 

We are now to consider these broader conse- Thepro- 
quences of the laboratory work: how it is affecting prietyofm " 

71 J ° quiring as 

our belief in the reality and the worth of the soul. It to the per- 

seems entirely suitable to take account of such things s ° "n C e° " s f ( ~ 

and to ask ourselves what effect certain doctrines will truth. 

295 



worth of the 
soul. 



296 Experimental Psychology 

have on practice or on belief. There are those, how- 
ever, who decry any questions of the kind. And cer- 
tainly we should all feel that such questions were out 
of place when asked as an immediate test and before 
accepting scientific results. But some would go to 
the length of saying that, even after acceptance, no 
honest man would for a moment ask himself what 
were the personal consequences of a doctrine; his 
interest would be confined merely to whether it were 
true or false. This heroic devotion to truth, regard- 
less of the effect the truth may have, would be more 
admirable, however, if it had not in it a touch of fanat- 
icism. There are religious and moral fanatics ; there 
are also scientific and intellectual fanatics — persons 
who are seized by this single, limited interest and 
see all things subordinated to it. For, after all, 
knowledge was made for man, and not man for knowl- 
edge ; and those who feel that truth is something 
ineffably sacred, and that in its presence man and his 
interests are not to be considered, simply commit on 
a grand scale the old fallacy of the miser who ends 
by worshipping the gold which at first he valued only 
for what it would bring. 

One may therefore be intellectually honest, willing 

to look the truth in the face, and yet be primarily 

interested in what the truth has in store for him and 

for those like him. 

Are the ex- A friend of mine, a man of great philosophical 

periments acuteness, is doubtful of the psychological laboratory 

founded on r J ° • i_i 

doubtful because he believes it to be founded on questionable 
metaphysics? me t a physics. He thinks that every one who experi- 
ments on mind, openly or tacitly commits himself to 



Spiritual Implications 297 

the doctrine of parallelism, 1 and that if parallelism 
should be disproved, all this work would be undone. 
The more common impression, however, is that the 
experimenters here must of necessity be materialists ; 
for there certainly is an air of materiality about any 
study whose chief engines of discovery are pendulums 
and chronoscopes. How can one hope to investigate 
the facts of mind with brass instruments unless he as- 
sumes that the facts of which he is in search are but 
a subtle form of material things. 

But the conclusion in each case is entirely wrong. The exacter 
One commits himself neither to parallelism nor to methods 

* commit one 

materialism nor to any special theory of the relation neither to 
of mind and matter by proceeding experimentally, norto^ 15 " 1 
Psychological experiments are but a special method parallelism, 
of making observations, and there is no more meta- 
physics implied in them than in ordinary introspec- 
tion or in the casual observation of a companion. If 
you were to conclude that your friend, on some occa- 
sion, was embarrassed because he blushed, no one 
would feel tempted to say that this inference of yours 
implied that you were a materialist or a parallelist. 
It is evident that your conclusion is not based on any 
particular theory of the connection of mind and body, 
but is drawn from the common observation that 
blushing and embarrassment often go together, and 
that you are reasonably safe in concluding that in this 
instance the one is a sign of the other. But, strangely 
enough, if instead of simply looking at his skin, you 
take a record by means of a plethysmograph, you are 
at once supposed to have surrendered to a metaphysical 

1 Cf. p. 278. 



298 



Experimental Psychology- 



No more is 

implied than 
in ordinary 
observation. 



theory. The new method, however, is simply a re- 
finement of observation, and the user of instruments 
of precision need have no different philosophy from 
one who only uses his eyes and his memory. 

Or, to take another illustration, we may observe 
that one person can learn in a few seconds what 
another cannot acquire in twice the period, — this 
without prejudice to the question of the ultimate 
nature of mind. But if instead of depending on my 
careless impression as to the time involved, I measure 
it by tuning-forks and smoked paper to a thousandth 
of a second, I am not thereby giving the work a ma- 
terialistic or parallelistic or any other bias. The fact 
that the subject presses an electric key when his 
mental act — say, of arithmetic — is complete, hides 
no more dangerous implications than if he were to 
utter the answer by word of mouth. Nor is it assumed 
that in careful experiments of this kind, the printed 
number presented to his eye causes only physical pro- 
cesses, and that the mental action is " parallel " rather 
than a result of the brain-action. All these problems 
are left open, to be decided on their own merits by 
whatever means are best adapted to their solution. 
We do not have to assume some answer to them in 
beginning our experimental work. 

With this brief consideration, therefore, I shall dis- 
miss this first question by saying that our laboratory 
work does not require us to take for granted that 
mental phenomena are at bottom facts of matter, 
nor do we have to assume that mind and body are con- 
nected in some particular way. Questions like these 
are in exactly the same status, as far as bias is con- 



Spiritual Implications 299 

cerned, as if we confined ourselves to simple obser- 
vations of our own mental phenomena and those of 
others. The laboratory psychology makes no strange 
assumptions ; it is not in some mysterious way a 
device of materialism, or of something equally dubi- 
ous. It is simply a better way of doing what men 
have always done in the study of mind. 

We may therefore pass on to the next question, as 
to the actual effect of such laboratory studies upon 
the belief in the existence of the soul. 

The new psychology, with its physiological and "Psychology 
laboratory methods, is often referred to as "psy- sou i» U j S a a 
chology without a soul." Later we shall see that just expres- 
this expression is half untrue, but yet it does seem to extent. 
me to be in some ways an excusable designation of 
the work; it really is, to some extent, "soulless," in 
the sense in which this word is applied, for example, 
to corporations : it goes on its way with but little 
heed to moral or religious considerations. All those 
ways of looking at things by which their personal 
value is taken into account are sedulously avoided. 
So that psychology is, indeed, a heartless, unemo- 
tional way of regarding even our most cherished 
spiritual affairs. Just as the physician may lose sight 
of the person, in his interest in the " case," so psy- 
chology deals with the facts of the mind in a cold, 
impersonal way ; it is interested in facts rather than 
in duty or in human welfare. 

But in a more technical sense the study might be The former 
called " psychology without a soul." As a friend of ° e go.° 
mine sat one day in his garden, a pedler, who had 



3°° 



Experimental Psychology 



The nature 
of scientific 
explanation. 



evidently seen better days, passed in, and noticing 
that he was reading a book on psychology, asked 
whether the present-day writings of the kind had 
much to say about the "ego." My friend had to con- 
fess that the ego had fallen somewhat into neglect. 
In the older days of psychology, whenever there was 
an especial difficulty that had to be overcome, it was 
easy to appeal to the ego, or the soul. It was a deus 
ex mdchina> called in when the situation became par- 
ticularly untoward. And, indeed, does it not seem 
a valid mode of explaining a mental occurrence, such 
as an act of will or the recollection of an event, to 
say that the mental process occurs because the self 
is there to produce it ? 

The great objection to introducing the self as a 
means of psychological explanation is, that the ego 
is not a particular mental process among other pro- 
cesses ; it is not an event in experience, out of which 
other events may flow. The older attempts to em- 
ploy it in scientific explanation were very much 
like accounting for the climate of California by say- 
ing that nature causes it. The statement may be 
true enough, but it is not enlightening. What we 
wish to know is, what particular features of nature 
bring such mildness of summer and winter; and if 
the Japan current can be shown to be responsible, 
the state of things becomes relatively intelligible. 
But nature is a collective system of occurrences, and 
to use it as a principle of explanation would be equiv- 
alent to saying that "the All" does some particular 
thing. We do not understand the special phenom- 
enon any better after hearing such an utterance than 



Spiritual Implications 301 

before ; we are still in the dark as to the antecedents 
from which the facts in which we are interested 
spring. 

So it is in psychology. The reason why the special- The soul is 
ists are often ready to accept the paradox that the ^eiesshere 
soul may here be left out of account is simply 
because it is, scientifically speaking, of no immediate 
assistance in explaining mental events. The soul is 
not a particular mental phenomenon among other 
phenomena. It is, rather, the personal system within 
which my particular mental events occur. It bears 
the same relation to the particular facts of my 
mind that nature does to the events of the physical 
world. And just as the various sciences, while all 
the while concerned with nature and her ways and 
history, nevertheless, in a sense neglect her, in that 
they never refer to her as the cause or explanation 
of particular events ; so our modern psychology is 
learning to proceed without the soul. Not that in a Yet a deeper 
further study one finds no evidence of its existence, negiecuhe * 
nor does in any true sense neglect it, nor ever can soul, 
neglect it. Every new fact in the mental life, and 
every new context that is revealed, does in reality add 
to our knowledge of the soul. But the psychologist 
has rightly recognized that his work must be to seek 
for precise and particular causes in the mental realm, 
and never to rest satisfied with attributing the event 
broadly to the ego, or self. The current phrase, "psy- 
chology without a soul," simply means, then, that in 
the treatment of the mental world after the manner 
of natural science, the mind as a whole is not to be 
employed as an explanation of particular mental occur- 



302 Experimental Psychology 

rences ; it is not a phenomenon among phenomena ; 
in the limited, scientific sense of the word, it is not 
the cause of its own occurrences. 

But if not a But men are influenced by the phrases they em- 
cause* wh pl°y> anc * the mere words in which this thought is 
believe in the clothed will probably encourage the notion that the 
soul is something in which the enlightened mind no 
longer feels called upon to believe. To say that in 
the more recent treatment of psychology there is no 
immediate use for any deeper reality than our desires 
and ideas, and that if the soul exists, it certainly is 
not a cause in the scientific sense, sounds not unlike 
the assertion that it is not a cause in any sense what- 
ever. And this would be equivalent to saying that 
it does not exist. For no one will long believe in 
anything that is not causal and active. The sign oi 
reality is that it can do something. When it ceases 
to be of influence, it ceases to be. So that it is im- 
portant that we keep before us the fact that the soul, 
in spite of its disappearance from psychology, has 
not disappeared from the earth. It is, indeed, the 
most active thing with which we have any direct 
acquaintance. And our modern psychology, while 
waving farewell to the soul with one hand, is, in 
truth, earnestly beckoning it back with the other. 
The modem For, in the first place, students are beginning to 
view is not so ^ e aware fa^t the mind can never be treated in 

soulless as 

theoidasso- its fulness so long as we conceive of mental phe- 

ciatiomsm. nom ena too closely after the analogy of physical 

events. From the time of Hume and Hartley, even 

down to the present day, there has been a school of 



Spiritual Implications 303 

psychologists who believed that they could adequately 
describe the mental life somewhat after the manner 
of our present nebular hypothesis in astronomy. 
Just as the prominent celestial bodies are due to the 
aggregation of numberless particles of disseminated 
matter called star-dust, so the mind was conceived as 
beginning in a kind of scattered idea-dust — minute 
and chaotic psychic elements, or sensations — which 
gradually collected into more or less stable groups 
until there finally emerged, by further thickening and 
more complex groupings, an orderly system of expe- 
rience with its ideas, its emotions, and its reasoned 
acts of will. This good old associationist view ought 
really to have been called psychology without a soul; 
for the most real things in the mental life, according 
to this conception, were the constituent elements, the 
primitive sensations, and whatever mind there was 
came from the assembling of these individual sensa- 
tions. The soul was simply a collective term for 
the numberless minute impressions which came and 
went, no man could say whence or whither. 

It is not difficult to appreciate what a chance affair The older 
the mind was, according to this view. The soul had doct " ne 

' ° was hostile to 

no inherent power; it had no inherent stability; it our higher 
was entirely a creature of circumstances. Morality interests - 
was a matter of custom ; immorality was not to be 
seriously considered. 

The essential features of such a doctrine, however, Persons 
have not been confined to the psychologists. Much ™^ e * s 
of our current popular thinking runs the same course, unreal. 
The influence of society upon the individual is often 
represented as if, surrounding us all, there were a 



3°4 



Experimental Psychology 



Mental phe- 
nomena 
regarded as 
acts of 
persons. 



great stratum of impersonal thoughts, a mental atmos- 
phere that had its own storms and sunshine. From 
this would be explained the common impulses, the 
passing styles of thought, the " movements " that 
pass like a wind over the minds of men. Those 
who believe in thought-transference often have a 
similar view ; thoughts seem to them to be relatively 
separate and self-existent things that can literally 
pass from one mind to another. The mind is viewed 
as a kind of receptacle for thoughts, as in that 
classic figure where each of us is likened to an aviary, 
and our thoughts to imprisoned birds. 1 And just as 
the birds may escape from one man's enclosure to 
that of another, or perhaps fly about and be possessed 
by no one at all ; so our thoughts are pictured as 
though capable of existing separate from the mind, 
and we as simply their temporary assembly. In 
Oriental philosophy there is a kindred belief. The 
individual is but a drop, separated, for the time, from 
the mother sea of impersonal life into which, in the 
end, he is to return. The common feature in all 
these conceptions, otherwise so different, is that the 
person is less enduring and important than the con- 
stituents that enter into him. He is but the artificial 
form which they assume. He is but a temporary 
group, or product, of psychic facts that can quite as 
well exist in an impersonal way. 

One may truthfully report, I think, that this con- 
ception has for many years been losing ground among 
psychologists. The ascendant view, and the one 
that seems to me by far the more convincing, is that 



1 Thecetetus, Steph., 197 et seq. 



Spiritual Implications 305 

sensations and judgments and memories, and all 

things else in our mental life, are to be conceived, 

not as self-complete and relatively independent 

things, but as acts of a living being. The analogy 

of particles of matter grouping themselves into 

objects cannot be made to apply to mental processes. 

The changes in the moral world are not a mere 

reshuffling of older entities. The mind can no more 

be constructed out of small pieces of ideas than the 

living body can be conceived as resulting from a 

gradual assembling of scattered heart-beats, with, 

later, a stray digestion and the rest. The relative The soul is 

standing of the soul and its sense-impressions is thus nota P roduct 

r of sense- 

entirely reversed. The mind is the deeper and more impressions. 

permanent reality, and mental phenomena are its 
ways of behavior. It has power and activity from 
within. It is not a mere creature of circumstances, 
— not a mere eddy in the endless stream of sensa- 
tions, — it is an agent, a person, facing the world, 
and acting upon it with will and intelligence. In 
offering this conception that the mind is an active 
participant in the world of events, now conquering 
and now for a moment beaten back, but all the while 
a power as real as aught we know — in presenting 
such a view modern psychology is by no means 
justly to be called psychology without a soul. Nor Higher and 
is it to be called soulless because it does not speak of ce^s are" 
some spiritual reality separate and aloof from our intimately 
common life of mind — from our plans and disap- Jome ' 
pointments, our daily joys and pains. It is often 
popularly thought that the soul is separate from the 
mind ; that it is a substance in which are lodged the 
x 



306 



Experimental Psychology- 



Persons are 

the elemental 
facts. 



more dignified attributes of the spirit ; its conscience, 
for instance, and its ideals — what we sometimes call 
our spiritual nature. But there is really no reason 
to disjoin the higher and lower life in this way. We 
do not need a soul separate from our everyday mind, 
any more than we need two bodies, — one reserved 
for the state occasions of life. Conscience and ideals 
must be willing to come close to homely things, must 
live in touch with our commonest acts, or they may 
as well be wanting. So that in making no separation 
of the soul from our most familiar processes, psy- 
chology will do the spiritual life no harm. 

I feel, then, that as far as the reality of the soul 
is concerned, the new psychology is in advance of 
the old. It makes the mind a living, a personal, 
thing. Every thought that arises, every emotion that 
stirs, is significant only as part of the larger life of a 
personal being. Persons are the elements of reality; 
they are not products, nor drift. The mind is not a 
mechanical interplay of psychic atoms ; it is a living 
whole. 



But persons 
are subject 
to psycho- 
logical laws. 



Some may feel, however, that while modern psy- 
chology is thus recognizing the reality of the per- 
son, it is to some degree undoing this good work by 
reducing the behavior of the person, as far as possi- 
ble, to law. The old notion of the " uniformity of 
nature," which has been so helpful in investigating 
physical things, is now quite generally extended so 
as to apply to the mental realm as well. The uni- 
formity of mind, in the sense that like circumstances 
lead to like results, has now become the general 



Spiritual Implications 307 

principle upon which the experimental work in psy- 
chology is based. And this uniformity of mind is Experi- 
not just taken for granted and there left, but it is, ^f^" 
as time goes on, receiving considerable verification, this. 
The preceding chapters have attempted to describe 
certain discovered regularities of this kind which 
seem to be quite as constant modes of mental action 
as are the laws of the physical world. Thus you 
may recall the simple instance that all persons note 
the difference between things more readily when the 
facts are brought to the mind in succession than 
when occurring at the same time ; or that the mind 
is universally subject to illusions, due to certain 
habits of interpreting our impressions of sense. 
These are laws of mental operation, and our study 
of mind is steadily enlarging the area within which 
such uniformity of action is observed. The more 
we become acquainted with ourselves, the more of 
these machine-like regularities we discover; until 
the thought is forced upon us that this constancy of 
behavior under like conditions is an absolutely uni- 
versal feature of mind, and that where we fail to find 
it we must simply conclude, not that it does not there 
exist, but that our eyes have not yet become sharp 
enough to detect it. We must therefore ask our- Does not this 
selves whether regularity of this kind in our mental mec ^ anical 

& J regularity de- 

actions does not make personality a less noble thing, tract from 
and especially whether it does not endanger our ^0™^? 
belief in human freedom and responsibility. 

To many persons, and perhaps to all of us in cer- 
tain moods, a view like this where uniformity reigns 
is cheerless enough. Life seems to have been robbed 



308 Experimental Psychology 

of some of its interest. There is nothing in store that 
is not somehow prefigured in our present mental 
states. A touch of unromantic calculability under- 
neath all seems to take from our spiritual dignity 
and to make us appear to play a puppet's part in life. 
The value of And yet I cannot feel that the thought of pervasive 
d? end^on re g u l ari ty should in itself detract from the charm or 
novelty. value of life. One may lay too much stress on the 

element of surprise. It is undoubtedly true that we 
are quickened by meeting the unforeseen ; but our at- 
tention and interest is not wholly dependent upon 
such stimulants. Home-coming, or the intercourse 
with old friends, is' attractive out of all proportion 
to the novelties we discover. The preference of 
children for an oft-repeated tale reveals the same 
trait. They are so familiar with its course that they 
mark the slightest departure from the original form, 
and yet they will have the old story rather than one 
where much is new. And certainly our serious moral 
interests are even more firmly based on other things 
than novelty. The affection which the mother bears 
her child does not require the intellectual spur of the 
unexpected ; it may persist even in a heightened de- 
gree where the child has met some check in its 
mental growth, and where all hope of change has 
finally died away. Or if the child develops in the 
sound way in which the mother expects he will, this 
does not hinder her attachment. Those who pity 
God because, as they suppose, he sees the end from 
the beginning, do not understand the psychological 
foundations of interest and love. 

The ennui, therefore, with which some anticipate 



Spiritual Implications 309 

a life unfolding according to law, is but a feeling of 
the idle hour. The train of events looks tiresome 
because we assume toward it, for the time, something 
of the novel-reader's attitude. But in actually living 
it we drop this fine intellectual or aesthetic air, and it 
becomes more and more a matter of moral relations, 
a matter of loyalty, of responsibility, of personal 
affection. 

The fear that the progress of life according to strict Yet surprises 
rule would steal its charm is groundless, moreover, enou & h are 

' ' m store. 

not alone because, as I have tried to show, the inter- 
est in living does not depend on sudden and unex- 
pected turns, but because in the very nature of 
things surprises are sure to come. The natural law 
of the mental life is, after all, a thing infinitely com- 
plex. Even if our knowledge of it were many times 
extended, the feeling that regularity makes life dull 
and tame would be like the notion that one's interest 
in the human face would of necessity cease because he 
had discovered the way in which our features are 
always arranged. Back of the simple scheme of two 
eyes, a nose, and a mouth, are the endless specific 
modes in which this formula may be fulfilled. No 
two faces alike, and yet all modelled on the same 
plan. 

But not only will the fulness of the mental life Higher 
never be exhausted by our rules, since the ways in jS? th J rays 
which the simplest scheme or law may be embodied unexpected, 
are endless, but the nature of mental growth is such 
that we have no way of telling what many of its laws 
will be until the slow progress of events brings them 
actually into effect. Most of our natural laws, as 



310 Experimental Psychology- 

well as our psychological laws, are not, for us at least, 
like Platonic ideas, existent in perfection from all 
eternity. They are what has been termed " contin- 
gent truths " ; they are simply our way of describing 
our life as the life itself unfolds. And this growth is 
always taking new directions, revealing new features 
that could never have been anticipated from our knowl- 
edge of the formulas that sufficed for the earlier 
stage. The laws that are sufficient to describe, for 
instance, the behavior of fire and air and water be- 
fore there was life upon the earth, give no hint, so 
far as we can see, of the wonders of vegetation. And 
probably we might fully formulate the changes of 
plants without their laws implying that consciousness 
would ultimately appear upon the scene. When these 
higher stages are reached, we see that they rest upon 
the lower, that there is no absolute disconnection. 
And yet, along with the continuity, there is something 
entirely new. After the event, we can see that the 
conditions for its coming have been in long prepara- 
tion, but we could never have assuredly foretold its 
coming from a natural-science knowledge of the ante- 
cedent facts. The preceding events are apparently 
necessary for its coming, but they do not produce it ; 
it is, after all, in some respects a gratuity, an act of 
supererogation, of the universe, 
illustrations The inner development of the mind itself shows 
chicndcT similar stadia of growth, similar incomings of higher 
functions, which the simpler forms of mental life had 
given us no reason to expect. The feeling of musi- 
cal harmony might serve as an illustration of what 
I mean. The pleasure we take in certain musical 



Spiritual Implications 311 

chords is more than the mere perception of the 
sounds that enter into the chord; it is even more 
than the power of comparing the impressions and 
of appreciating that they are of different pitch ; it is 
more, too, than the sum of the pleasures we get from 
individual notes. It is an absolutely unique experi- 
ence, a unique mode of appreciating the tones, which, 
so far as we can now see, the mind might have lacked 
through all eternity, and no one could justly have 
said that the earlier life had given promise of some- 
thing which the later facts had failed to fulfill. Of 
a similar nature is memory — the conscious survey 
of the past, — as well as the pleasure of imagina- 
tion. They slowly and silently appear in the history 
of the race ; they are built, in the closest way, upon 
the earlier mental foundation, but they are not neces- 
sarily implied in its earliest form. Out of the depths 
of the mind, new powers are thus always emerging. 
Until they are awakened, neither apparatus nor 
scrutiny will show that they are there. When we 
understand our life more fully, therefore, we find no 
ground for supposing that the laws of the present, 
or even of any future time, will take the interest from 
what is still to come. There seems always to be 
something held in reserve, and no amount of science 
can ever take from the world the element of wonder. 
It never will become as a tale that is told. 

But if the constant presence of law still seem in Psycho- 
some way a menace to our power and responsibility, l °^^ a,vrs 
we must remember that laws are not forces externally external 
compelling us to behave contrary to our own nature ; orces ' 
they are mere descriptions, mere statements, of how 



312 



Experimental Psychology 



They are 
compatible 
with human 
freedom. 



Are these 
laws subject 
to amend- 
ment ? 



the mind actually does behave. Definite character 
always presupposes some specific mode, or law, of be- 
havior. Indeed it would be difficult to conceive of 
a personal existence of any kind that would be 
lawless, in the scientific sense. If, then, we were 
to suppose free beings to exist, we should natu- 
rally expect them to reveal some inner law. We 
should expect them to have a definite nature, to 
show constancy and system, and to act with refer- 
ence to what was present and what had gone before. 
When, therefore, our observation of ourselves actu- 
ally brings out what these definite forms of action 
are, we certainly cannot use these discoveries as 
evidence against the reality of freedom, with which, 
in truth, they so well accord. Here as elsewhere, 
therefore, law and liberty are compatible and even 
inseparable. At first the effect of psychology is to 
encourage the notion that everything is mechanical, 
and that no place is left for personal force and will. 
The very regularity of nature revives the belief in 
fate. Further insight, however, shows that we do not 
have to choose between persons and law, but that 
personality itself is the most perfect example of law. 
Our instinctive distrust of law, however, does not 
spring wholly from its long association in our minds 
with the impersonal powers of nature, with forces 
that have no regard for the sufferings and desires of 
men. In part, at least, it may arise from our experi- 
ence with human governments. No political consti- 
tution has ever been devised broad and elastic enough 
to suit forever the character of a changing people. 
There comes a time when a violent disruption alone 



Spiritual Implications 313 

can bring the constitution into accord with the 
nation's new life. But when we turn from political 
government to the constitution of the world of things 
physical and mental, it seems as if this larger order 
of things were neither subject to amendment nor 
capable of change by revolution. The whole seems 
fixed beyond our utmost power. So that we perhaps 
unconsciously feel that rigidity like this can never 
give lasting satisfaction to a living and growing 
mind. 

But, as I have tried to show, this fixity can easily indications 
be overstated as regards the inner constitution of the of s s "ufj t a 
mind. Its laws are, to some extent, like those of a 
healthy state, subject to new enactments as new situ- 
ations arise. And probably beyond the limits of our 
present knowledge there are conditions that are even 
better adapted to our growth. May it not be that 
death itself is just such a period of adjustment, when 
there come into effect new laws, both inner and 
outer, that are better suited to the altered wants of 
the person. Looked at from every side, it seems 
clear that natural law need never be found to be a 
check upon our growth. Especially as it is revealed 
in psychology, it is the sign and evidence of the 
deeper life within. 

This is the bearing of recent psychology, it seems The general 
to me, on the reality and worth of the soul. These bear * n s of 

' J psychology. 

great doctrines are certainly in no real danger from 
the modern scientific treatment of mind. Indirectly, 
the work ought to strengthen our confidence in 
spiritual things. It is, itself, a sign of a growing 
interest in the mind, and will react and stimulate the 



/ ; 



314 Experimental Psychology 

interest from which it springs. It is already assist- 
ing us to recover from that almost exclusive attention 
that has been given for so many years to the parts 
of nature that are below the human plane. And in 
the end it will be clear that man can never be 
understood until he is regarded not simply as a 
physical fact, nor merely as a group of psychological 
phenomena, but as a centre and source of activities — 
as an underlying reality — of which the special occur- 
rences with which our laboratory experiments are 
busied are but surface and outcrop. 



INDEX 



The following abbreviations are used: exp., exps. for experiment-al, experiments; 
phen. for phenomenon, phenomena; psych, for psychology, psychological-ly. 
Other abbreviations are self-explanatory. 



Abstractions, deference due, 231. 
Accuracy of mental measurements : 

doubts in regard to, 56 ; may be 

overvalued, 57. 
Activity : as test of the real, 302 ; of 

the mind, 119-21, 163. 
Acts, psych, phen. regarded as, 71, 

3°4- 
Advertisements, psych, of, 217. 
^Eneas, expression of his emotion, 

269. 
Esthetics, vs. psych, of beauty, 227. 

See also Art; Beauty; Pleasure. 
Affection : and the unexpected, 308 ; 

parental, 308. 
After-images : duration of, 21-6, 

40-1 ; of color and motion, 97. 
Allen, Grant, 246. 
Alliteration, 255. 
Alterations of personality, as evidence 

for the unconscious, 70, 75-9. 
Amendment of psych, law, 312-13. 
Amiel, morbid introspection of, 3. 
Analogy between brain and mind, 

misapplied, 80, 81. 
Anatomy : of sense-organs, and the 

space-threshold, 125 ; of brain, 

271-6. 
Angell, F., 172, 178. 
Angels, their memory, ace. to Dante, 

198. 
Angles, illusion from subdivision of, 

152-3- 
Animals : their space-perception, 161 ; 
memory, 183, 190-1 ; recognition 
and dreams, 191-2. 

3 



Aphasia, 273. 

A priori method, 163, 285. 

Arc, illusion of interrupted a., 117. 

Aristotle : and the " New Psychol- 
ogy," 1 ; A.'s illusion and its con- 
verse, 103-4, 113; concerning seat 
of consciousness, 271. 

Arithmetic, mental: its effect on cir- 
culation, 266. 

Arm, volume of, under different 
conditions, 264-5. 

Art : and memory, 191 ; philosophy 
vs. psychology of, 227; requires 
more than unity in variety, 248; 
"flesh" and "spirit" in, 249; 
Wagner's place in, 257 ; Greek 
and modern, 257; of pure color, 
258-60. 

Arts : differentiation of, 249-61 ; di- 
vergence of color and drawing 
in, 253-4; auditory, 256; visual, 
257-60. 

Asceticism, opposed by modern 
psych., 270. 

Association, cerebral, in infant, 276. 

Association, mental: memory and 
verbal association, 29; in space- 
perception, 143 ; hindered by in- 
tensity of impressions, 255; 
importance of, 274-5. 

Association-theory : in exp. psych., 
6; limitations of, 102; of space, 
122; and the soul, 302-4. 

Association- time : shortened by limit- 
ing the range of association, 42; 
not primarily physiological, 59. 

*5 



3i6 



Index 



Assumptions, in psych, exps., 296-9. 

Astronomers, as experimenters in 
psych., 7-8. 

Astronomy: relative accuracy in a. 
and psych., 57 ; analogies in psych, 
drawn from, 303. 

Athearn, exps. by, 215. 

Atmosphere, mental, 304. 

Attention : affected by subliminal 
stimuli, 90-1 ; illusions from stress 
of, 98-102 ; direction of, influences 
movements, 203-4; and color- 
preference, 230; pulse of, 233-6; 
in linear grace, 239-41. 

Automatic writing and speech, 76-9. 

Automatograph, 205. 

Automaton, the body as an, 279. 

Ave Maria, in Mosso's exps., 268. 

Aviary, the mind as an, 304. 

Background, the mental, 83, 87. 

Bacon, Francis, 4. 

Bakewell, vi. 

Baldwin, J. M., and imitation, 199, 
206. 

" Bar," in imaginary rhythm, 232. 

Bashkirtseff, Marie, 3. 

Beatrice, 198. 

Beauty: sense of, an ultimate fact, 
164; aesthetics vs. psych, of, 227; 
character of experimental work on, 
227-46, 260; factors in enjoyment 
of, 247-8. 

Beethoven : Choral Symphony, 61 ; 
Fifth Symphony, 257; Fate at the 
door, 258. 

Belief, influence of, on the power of 
the individual, 210. 

Benefits forgot, 193. 

Bentley, 172, 178. 

Berenson, 214. 

Berkeley : in the history of exp. 
psych., 4; his " New Theory," 4-5, 
128-31; surgeon's exps. to test his 
view, S ; the world as visual lan- 
guage, 105. 

Berlioz, his descriptive music, 257. 

Bertino, exps. on the brain of, 266-8. 

Bessel, and personal equation, 8. 



Binocular depth, 135-7, 187. 

Birds : vision, 137 ; thoughts likened 
to, 304. 

Blind-spot, imaginative filling-in of, 
214. 

Biind, the: their space discrimina- 
tion, 45-7 ; exps. on, after surgical 
relief, 129-35, 144-5 ! as living in a 
time-world, 139-40 ; value of im- 
pressions for, 181-2; interest in the 
voice, 182 ; dreams, 182. 

Blood, circulation of, under diff. 
psych, conditions, 264-8. 

Body, the : inference from ear'.y 
organization of, 162; responsive 
to mental states, 206; affected 
by imitation, 219-20; not a clog 
upon the mind, 270; seat of 
consciousness in, 271-5 ; paral- 
lelism implies uselessness of, 
282; real importance of, 293; 
connection of the mind and, Ch. 
XIV, 262-94. See Mind and 
Body. 

Bolton, 233. 

Books, compared with personal in- 
tercourse, 218-19. 

Boswell, 212. 

Bourdon, 125. 

Bradley, 53-4, 282. 

Brain : cerebral localization, 9, 
271-6; motor zone, 273; sensory 
centres, 274 ; cooperation of parts 
of, 275 ; subliminal stimuli, 79-81 ; 
Mosso's exps. on, 265-8 ; seat of 
the soul, 271-3 ; infant's, 275 ; is 
not mind, 277; interaction and 
parallelism of mind and, 278-91. 
See Mind and Body. 

Brand, vi. 

Bridgman, Laura, brain of, 274. 

British: interest in psych., 4; view 
of space-perception, 122. 

Broca, and brain localization, 9, 
272-3. 

Brown, 125. 

Browning, quoted, 235. 

Buddhism, ref. to, 66, 304. 

Bunnell, exps. on blind, 46. 






Index 



3 l 7 



Cagliostro, communications osten- 
sibly from, 77. 

Carlyle, 68. 

Car-window illusion, 102-3. 

Cataract, exps. after operation for 
congenital, 129-35, 144-5. 

Categorical imperative, 163. 

Catholic dogmas, basis of certain, 
219. 

Cattell : on recognition of colors, 41 ; 
on mental measurements, 65. 

Causation : discovery of, the purpose 
of mental measurements, 64; in 
memory, 188 ; objection to inter- 
action from idea of, 283-87 ; Hume 
on, 286 ; as test of reality, 302. See 
also below. 

Cause and effect : the relative dignity 
of each, 277 ; equivalence of, not 
axiomatic, 283-4. 

Cheselden's case, 5, 129, 144-5. 

Chicago Fair, color preferences at, 
230. 

Childhood, reference of events to, 
185, 188. 

Children : space-discrimination of, 45 ; 
development of brain, 275-6; their 
verses, 255 ; " pure " sensations in, 
162; value of child-study, 184; 
memory in, 191 ; learn by sugges- 
tion, 217-18, and by imitation, 
222 ; do not imitate all things alike, 
223 ; personal differences in, shown 
by what they learn from their com- 
panions, 223 ; color preferences, 
229-30; early consciousness dis- 
jointed, 276 ; education of, as treat- 
ment of nerves, 293; liking for 
oft-told tales, 308. 

Choral, units of interest in, 235. 

Choroiditis, effect of, 138. 

Chronometric work, 37-43. See also 
Measurements, mental. 

Church, power of, 219. 

Circulation of the blood, changes in, 
264-8. 

Cognitio vespertina, matutina, 196. 

Color : in impressionistpainting, 249 ; 
and differentiation of Fine Arts, 



Ch. XIII, 249-61 ; sense of, un- 
stable, 250-1 ; and space, per- 
sonal equation in, 251 ; rivalry of 
c. and drawing in art, 253-4; 
vividness of, with loss of meaning, 
254; in ancient sculpture, 257; 
art of pure c, 258-9. See also 
below. 

Color-blindness : in infancy, 250 ; in 
margin of vision, 250; total, 251. 

Color-contrast : measurement of, 43- 
5, 56-8, 61-2 ; heightened by lack 
of definiteness, 58. 

Colored sounds, 252. 

Colors : Goethe's exps. on, 7, 18 ; 
memory for series of, 28-9 ; exp. 
on " complication " of c. and 
sounds, 99-100 ; change of, due to 
disturbance of recognition, 101, 
254 ; comparison of, 175 ; of shad- 
ows, 43, 214 ; preferences, 229-30 ; 
harmony of, 243, 246-7. 

Comparison, successive vs. simulta- 
neous, 175, 178. 

" Complication " of sound and color, 
99-100. 

Conduct : influence of recollections 
on, overestimated, 193; and one's 
scale of values, 194-5. 

Conscience, relation of, to the rest 
of the mind, 164, 306. 

Consciousness, and brain-cortex, 39- 
40, 123, 271-6, 289. 

Conservation of energy, as objection 
to interaction of mind and body, 
287-8. 

Constructiveness, seat of, 273. 

Contagion, mental, 218. 

" Contingent truths," 310. 

Convolutions, cerebral : as seat of 
consciousness, 272; third frontal, 
273 ; cooperation of, 275. See 
also Brain. 

Correspondence : of mind and body, 
162; of mental and cerebral pro- 
cesses, 289. 

Cortex, cerebral, and consciousness, 
39-40, 123, 271-6, 289. See Brain. 

Crime, as cerebral disease, 293. 



3i8 



Index 



Cross, Roman and Greek ; aesthetics 

of, 244. 
Crow-bar case, 272. 
" Curve " of forgetfulness, 168. 
Curves, pleasure in : eye-movement 

theory of, 237; exps. showing 

source of, 238-42. 
Custom : as a source of illusions, 

102-5, 107 ; role of, in harmony of 

senses, 151. 

Dante : memory of angels, 198 ; terza 
rima of, 255 ; appearance of blest, 
294. 

Darwin and Heraclitus, 1. 

'* Dead time " in reaction, exps., 39- 
41. 

Deaf, the : value of different impres- 
sions for, 181; dreams of, 182; 
laughter of, 202. 

Death and psych, law, 313. 

Defeat, suggestion of, unpleasant, 
240. 

Delirium, images in, 97. 

Delusion : regarding magnets and 
insanity, 93 ; and illusion, 118. 

Democritus, a friend of sense, 249. 

Dependence, personal, and inde- 
pendence, 221-2. 

Depravity, intellectual, and illusions, 
115-6. 

Descartes, and seat of soul, 272. 

Deutschmann, Christine, dreams of, 
182. 

Development : place of memory in 
mental, 188-198 ; of fine arts, 255- 
60; of brain, 275-6. 

Differences, imperceptible, in psych. 
may be real, 84-5. See Discrimi- 
nation. 

Direction : sense of visual, 136 ; 
harmony of touch and sight as 
regards, 145-9. 

Discords, harmonies and, of space- 
perception, Ch. VIII, 142-64. See 
Music. 

Discrimination : Weber's Law of, 11 ; 
in nicker exp., 25, 40-1; spatial d. 
measured, 45-7; exps. on, as evi- 



dence for the unconscious, 83-88 ; 
discriminative to absolute thresh- 
old, 86. 

Disorder, unpleasantness of, 240. 

Dispositions, psychic, and memory, 

74-5- 

Distance : sense of, 136 ; the blind, 
and perspective, 140; factors in 
judgment of, 186-7; suggestion 
and, 214. 

Distinctness, in psych, of time, 185-7. 

Distortion, heightening of color by, 
101, 254. 

Distortion, in memory : distinguished 
from blurring, 170; reasons for, 
only partly understood, 173. 

Divinity, and embodiment, 294. 

Divisions in psych., artificial, 119. 

Dixie, recognition of, 183. 

Dogs : sight vs. smell, 183 ; recogni- 
tion of places, 191-2. 

Donaldson, 274. 

Drama, music and, 256-7. 

Drawing vs. color, in art, 253-4. 

Drawings of objects seen but an 
instant, 177, 215. 

Dreams : and spontaneous stimuli, 
96-7 ; bearing on multi-personality, 
78 ; cross-examination in court, 78 ; 
how distinguished from reality, 113- 
14; their place in psych, reality, 
115; of the blind, 182; of the 
deaf, 182 ; usually not reminiscent, 
191 ; animals', 191 ; children's, 191. 

Dress, styles of, and suggestion, 216. 

Drugs, psych, effect of, 292. 

Dufour's case, 130. 

Dunan, and the visualists, 139-40. 

Dunlap, vi ; exps. with imperceptible 
shadows, 88-90. 



Ebbinghaus, exps. on memory, 166- 

169. 
Education, see Children. 
Ego, modern neglect of, 299-300. 
Elements, psychic, 303. 
Ellipses, preferred proportions in, 

244. 



Index 



3*9 



Emerson, on memory, 189. 

Emotion : in localizing events in 
time, 187-9; expression of, 263, 
268, 269. See also Expression. 

Energy, conservation of, as objec- 
tion to psycho-physical interaction, 
287-8. 

Enjoyment, see Pleasure. 

Error of mental measurement, 56-9. 

Euclidean geometry, space-illusion 
and, 152-7. 

Evidence, scientific attitude toward, 
94. 

Evil : fascination of, 220 ; has its 
source in both mind and body, 293. 

Evolution : objection to parallelism 
from, 281 ; relative importance of 
mind and body in, 292. See 
Development. 

Exactness, in psych, measurement, 
57; no absolute, in any scientific 
measurements, 57; lack of, does 
not prevent induction, 57. 

Expectation, in harmonizing touch 
and sight, 149. 

Experience: in illusions, 98, 100, 102, 
106, 107 ; involves logical circle, 
112; is its own criterion, 112-13; 
not a direct impress from without, 
1 19-21 ; place of space-element in, 
159-64; non-spatial e., 139-49; in 
space-perception, 143 ; in harmony 
of touch and sight, 149 ; illusions, 
as a part of, 156 ; always an ideali- 
zation, 156-7; yet it imperfectly 
conforms to both real and ideal, 
159 ; change of, in memory, 169-79 ; 
is less sensuous than is usually 
supposed, 176-9; maximum of 
clearness in, 179; requires reten- 
tion, 190; brain and mind as forms 
of, 291. 

Experiments, psychological : history 
of, Ch. I, 1-16; motives for rise, 
1-4 ; influence of British empiri- 
cism, 4-6; the Germans in, 7-16; 
of astronomers, 7-8 ; of physiolo- 
gists, 8; phrenology and, 9; We- 
ber's, 10-11 ; Fechner to Wundt, 



11-15; Lotze and Leibnitz, 15-16 ; 
general character of, Ch. II, 17-32; 
relation to physiological exps., 
17-27; analysis of flicker exp. to 
show distinction betw. physiologi- 
cal and psych, exps., 21-26; psych, 
exps. and higher levels of mind, 
27-31 ; apparently sensuous char- 
acter of, explained, 29-30; range 
of, 30 ; place in psych, as a whole, 
31-2, 297-8 ; ethical doubts aroused 
by, 295-314; based on doubtful 
metaphysics, 296-8. 

Explanation, scientific, 286-300. 

Exposures, effect of short, 177, 215. 

Expression, physical, of mental states : 
263-71 ; subtlety of, 264 ; records 
of vascular changes, 264-8; Mosso's 
exps. on living brain, 266; view of, 
revolutionized, 269 ; importance of, 
for emotion, 269; expression and 
mental states are one and insepa- 
rable, 269 ; gives us possession of 
our thoughts, 270; necessity for, 
294. 

Extension : consciousness of, is irre- 
ducible, 159 ; as inherent in sensa- 
tion, 160-3. See Space. 

" Eye and ear " method, 8. 

Eyes : effect of movements of, in 
perspective, 135-7 ; feeling while 
rolling, 238 ; photographs of eye- 
movements, 238-42. See Color ; 
Sight. 

Fact and fancy, not distinguished by 

vividness, 215. See Reality. 
Faculty : independence of, disproved 

by illusions, 100-1 ; memory not a 

separate, 189. 
" Faith without works," 270. 
Fallacy, logical, illusion and, 108- 

10; in all sense-perception, 109-10. 
Fanaticism, varieties of, 296. 
Faraday, on table-tipping, 205. 
Fatigue : in linear ugliness, 241 ; in 

color-appreciation, 246. 
Fechner ; and Psycho-physical Law, 

11-13 ; influence, 13 ; and Miiller, 



320 



Index 



13 ; contrr sted with Lotze, 15 ; as- 
sumptions, 48; exps. on aesthetic 
preference, 243-4. 

Ferrier, 9. 

Fillmore, on Indians' recognition of 
music, 133-4. 

Finger tips : minimal roughness per- 
ceived by, 125 ; blind man's feeling 

in, 135- 

Fish, their vision, 137. 

Flechsig: on cerebral localization, 
274; indebtedness to, 274; on 
order of development of senses, 
276. 

Flesh vs. spirit in art, 249. See Mind 
and Body. 

Flicker-experiment : analysis of, 
21-6; seems purely physiological, 
21 ; psych, features of, 22-6 ; as 
instance of mental chronometry, 
40-1. 

Flournoy, exps. on Mile. " Smith," 
76-8. 

Foot, poetic and psych., 233-6. 

Forgetfulness : what becomes of for- 
gotten ideas ? 71 ; rate of, 166-9 ! 
explained, 180. See Memory. 

Form, mental : vs. mental matter, 162, 
231,248; lacks intensive quantity, 
48 ; in perception, is from us, 120; 
almost absent in child, 276; enjoy- 
ment of, Ch. XII, 227-48; formal 
element in sensuous enjoyment, 
231, 248; elementary forms, in 
beauty, 232-43 ; partisanship re- 
garding, 249 ; and impressionism, 
250. 

Forms, spatial : memory for series 
of, 28-9 ; recognition of, 131-5. 

Franz's case, 130, 134. 

Freedom, and psych, law, 307-12. 

Frequency of light sensations, 21-6. 

Friends, enjoyment of, 308. 

Frog, hemisphereless, 279. 

Future, interest in the, 311. 

Gall, 9, 272. 

Galton's whistle, exps. with, 173. 

Genius : and imitation, 225 ; relation 



of, to his times, 225; as cerebral 

disease, 293. 
Geometry: modern, and the psych, 
of space, 122, 123, 152-7 ; Kant on, 

155. 

Ghost, popular conception of, 270. 

God, foreknowledge and interest, 
308. 

Goethe's experiments on color, 7, 18. 

Golden Age, psych, of, 171. 

Golden ratio : in rectangles, 243-4 ; 
in musical tones and time-divi- 
sions, 245 ; why pleasing, 247. 

Goltz, 9. 

Good and evil, derived from others, 
221. 

Gottingen, work at, 13. 

Gracefulness, linear, exps. on, 237- 
42. 

Habit, mental: influence of, 19; 
profit and loss from, 43; and 
memory, 74-5 ; and physical, dis- 
tinguished, 75 ; in harmonizing 
senses, 151. 

Hallucinations: logic of, 109; of 
insane, 114; reality of, 115. See 
Illusions. 

Hand : space-perception by the, 138 ; 
tracings by the, 200-1. 

Hansen, 206. 

Harmony: as test of truth, 1 14-15; 
of touch and sight as regards 
distance, 142-5, direction, 145-9, 
and size, 149-51; mind as, 292; 
pleasure in various kinds of, 241-5, 
310-11 ; factors in, 246-7. 

Hartley, 6, 302. 

Hartmann, and the unconscious, 66. 

Hart's exps. on literary rhythm, 234-5. 

Harwood, 172, 178. 

Hearing : vs. understanding, 47, 213, 
275 ; as space sense, 142 ; memory 
for, 170-1, 173-4, 179-80, 181; 
recognition by, 183; cerebral 
localization of, 274; infant's, 275. 
See Music; Sound. 

Heart, and consciousness, 271. 

Hegel, mentioned, 7 ; on quantity, 55. 



Index 



321 



Helene " Smith," case of, 76-8. 

Heller, 46. 

Helmholtz, 5, 9, 243. 

Heraclitus and Darwin, 1. 

Herbart, 15. 

Hermann's " Hand-book," 9. 

Heubner's case, 275. 

Hirschberg, 178. 

History: distortion in, 174; clarifi- 
cation in, 178 ; influence of, not 
conscious, 193. 

History of psych, exps. Ch. I, 1-16. 

Hitschmann, on dreams of blind, 
182. 

Hobbes, 4. 

Hodgson's exps. on Mrs. Piper, 76. 

Hoffding, and the unconscious, 81. 

Home-coming, interest in, 308. 

Home : mentioned, 5 ; his case, 129, 

144-5- 

Homer: mentioned, 31; on mind 
and body, 262. 

Horse's recognition of places, 191-2. 

Howison : indebtedness to, vi ; on 
quantity, 55. 

Hume: 4; on space, 122; on causa- 
tion, 286 ; on mind, 302. 

Hypnotism : and impulsiveness, 208 ; 
and other normal phen., 210; post- 
hypnotic suggestion, 211 ; fear of, 
220; individuality in, 224; and 
the unconscious, 75. 

Idea-dust, 303. 

Idealism, and mind and body, 290-1. 

Ideals: in reality, 157, 159; and the 
rest of mind, 306. 

Ideas : are acts, not substances, 71, 
305; may be reenacted, 72; not 
unconscious, 83 ; are highly organ- 
ized, 83; recollection of, vs. return, 
165, or persistence, 190; fading 
of, 168-9; distortion of, 169-74; 
during forgetfulness, 71-169; are 
unstable, 169 ; are motor, 206, 209 ; 
importance of antithetic, 207-8 ; 
enjoyment of, 256; possession of, 
by expression, 270; mind not 
made of, 305. 
Y 



Illusion : Zdllner's, 53 ; revolving 
spiral, 97; weight-size, 98; suc- 
cession of sounds, 99 ; Aristotle's, 
and converse, 103-4; Miinster- 
berg's, 116; interrupted arc, 117; 
subdivision of angles, 152-3; par- 
allel lines, 153-4; three points, 
154; of shape and size, 154. See 
below. 

Illusions : and their significance, Ch. 
VI, 95-121; service of, 95; range 
and classification, 96-106; three 
groups are alike, 106; always in- 
volve misinterpretation, 106-7 \ 
inevitableness of, 107; how dis- 
tinguished from perception, 108- 
14, 157-8 ; a kind of reality, 114- 
15; and scepticism, 115; not 
annulled by detection, 116-18 ; in 
play and art, 118; main teaching 
of, 101, 119-21 ; spatial i. and real 
space, 155-7. 

lima S., case of, 71. 

Image, mental : development of, 177; 
imageless memory, 190. 

Image, retinal : least perceptible dif- 
ference in, 125 ; inversion of, and 
upright vision, 143, 146-9 ; why not 
conscious of, 143-5. 

Imaginary rhythms, preference 
among, 232. 

Imagination : a high achievement, 
190 ; imaginative filling-in of blind- 
spot, 214; a gratuity, 311. 

Imitation and suggestion, Ch. XI, 
199-226; and hypnotism, 209; in- 
voluntary i., 200; in movements 
of hand, 200-1 ; with and without 
sensible pattern, 202-3; in the 
schools, 218 ; in morality, 218 ; in 
religion, 219; sinister aspect of, 
220 ; and responsibility, 221-2 ; in- 
separable from originality, 222; 
individuality in, 223-4 '< " tne sincer- 
est flattery," 225 ; and genius, 225 ; 
destroys itself, 225 ; enjoyment of, 
230, 240 ; in music, 257 ; in paint- 
ing, 258. 

Immortality, and associationism, 303. 



322 



Index 



Imperceptible differences: in sensa- 
tion, 26; may be psych, real, 84-5. 
See below. 

Imperceptible sensations : affect con- 
scious processes, 88-90. See Un- 
conscious. 

Impersonal thoughts, 304. See Per- 
son. 

Impression, see Sensation. 

Impressionism in painting, 43, 249. 

Impulse : and hypnotism, 208 ; in- 
sistent, 211-12; Dr. Johnson's 
case. 212. 

Indians' recognition of music, 134. 

Individual : has a test of reality, 158 ; 
not absolutely plastic, 223, 226; 
varying influence of, 224; i. char- 
acter in imitating, 224; both imita- 
tor and pattern, 225 ; i. and society, 
221, 303-4. See Persons. 

Individualism, and modern psych., 
221. 

Infants : sensuous element in, 162 ; 
color preferences of, 229-30 ; brain 
of, 275-6; disjointed consciousness 
of, 276. See Children. 

Inference, in perception and illusion, 
108-11. 

Insane : delusion regarding magnets, 
93 ; images of, 97 ; and test of 
reality, 114. 

Insistent questions and impulses, 
211-12. 

Intellect: and illusion, 117; in ap- 
preciating time-order, 29, 188-9; 
growth of, and imitation, 219; in 
color preference, 230; rivalry of 
sense and, in the arts, 249, 256 ; in 
music, 257 ; and the moral relation, 
308-9; in linear grace, 239-40; in 
symmetry, 241. 

Intensity: measurement of, 43-5; 
most troublesome of mental quan- 
tities, 48-9, 62, 64; applies only to 
sensation and feeling, 48 ; does not 
imply that mental phen. are com- 
pound, 48-9; attempt to expel, 50; 
measurements of, suspicious, 60; 
units of, 60; subject to impercep- 



tible gradations, 86 ; change of, in 
memory, 170-1 ; memory for, 180-1. 
See Measurement; Quantity. 

Interaction of mind and brain : vs. 
parallelism, 278 ; and idea of causa- 
tion, 283-7 '» conservation of energy 
and, 287-9 1 philosophy and, 290-1. 

Interest : an ultimate fact, 164 ; 
rhythm of, in verse, 233-5 ; m 
music, 235 ; novelty vs., 308 ; in 
future, 311. 

Interplay of faculties, 119-21. 

Interpretation : fixity of, 102-5 '■> m 
perception, 104; in illusion, 106. 

Introspection : afundamental method, 
1-2, 31; difficulties of, 2-4; and 
exper. method, 17-18, 31 ; and the 
unconscious, 66-7 ; evidence of, 
not final, 86; as retrospect, 175; 
value of, 277. 

Inversion: hinders recognition, 133; 
of retinal image, and upright vision, 
143, 146-7. 

James, Wm. : 20; and the uncon- 
scious, 67, 93-4 ; on voluminous- 
ness of sensations, 160-3 '< n * s " Will 
to Believe," 211. 

Jastrow : on involuntary movements, 
205 ; on color preferences, 230. 

Jelly-fish, its freedom from illusions, 
108. 

Jenning's exps. on protozoa, 161. 

Job, poetry of, 255. 

Johnson, Dr., insistent impulse of, 
212. 

Judgment: affected by imperceptible 
impressions, 88-90; moral place 
of, 164; influenced by suggestion, 
217-19 ; is a personal act, 305. 
See Intellect. 

Kant: on psych, quantity, 34; on 
space, 122; on illusions, 155; il- 
lusions and his doctrine of geome- 
try, 155-7. 

Kennedy, 171. 

Knowledge : criteria of, and the un- 
conscious, 93-4 ; does not destroy 



Index 



3*3 



sense illusion, 117-18 ; aided by de- 
ception, 121 ; critical, vs. memory, 
195-7 ; relation of, to man, 296. 
Krafft-Ebing : case of lima S., 71 ; 
on suggestion, 212-13. 

Lady of Shalott, and illusions, 120. 

Landscape : contrast-colors in, 43, 
58 ; viewed abnormally, 101. 

Language : outer world as, 105 ; and 
thought, 217. 

Laughter of mutes, 202. 

Laus temporis acti, 171. 

Law : knowledge of, in memory, 
187-8 ; knowledge of, vs. memory, 
195-6. 

Laws, psych. : all persons subject 
to, 306-7 ; and human worth, 307 ; 
and prophecy, 309-10 ; as " con- 
tingent truths," 310 ; and responsi- 
bility, 31 1-12; amendment of, 312- 

13- 

Lehmann, 206. 

Leibnitz: and the new psychology, 
7, 16 ; and the " infinitely little," 
68-9; and the unconscious, 68-9, 
80-1, 82-91 ; individualism of, 221 ; 
and psych, of expression, 294. 

Leipzig, psych, work at, 14-15. 

Lenses, reverting, exps. with, 146-7. 

" Leopold," 77. 

Letters, memory for series of, 28-9. 

Leuba, 173. 

Life, value of, and novelties, 308. 

Lines: pleasure in, 237-41; pre- 
ferred divisions of, 244; vs. color, 
in art, 250. 

Localization, cerebral, of mental 
functions, 9, 271-6. 

Localization, conscious : of impres- 
sions, 123-5 1 finer than nerve 
differences, 126-7; ancl ocular 
paralysis, 135-6; and retinal dis- 
turbance, 138; vision vs. touch, 
142-9 ; in time, 185-9. 

Local signs, 124-7. 

Locke: and exp. psych., 4; and 
psych, of space, 122; Molyneux's 
query, 128. 



Logarithmic law, Fechner's, 12. 

Logic: and illusions, 108-n ; in 
time-judgments, 188-9. 

Lotze : his mind, 15 ; " Medicinische 
Psychologie," 15 ; as a physiol- 
ogist, 20; on impersonal experi- 
ence, 68 ; on interaction, 289. 

Lyric temper, the, 255. 

Magnetism and vagaries, 93. 

Man vs. woman, color preferences 
of, 230. 

" Man of one idea," and association- 
time, 43. 

Mars, communications ostensibly 
from, 77. 

Masterpieces of art, why exps. neg- 
lect, 228. 

Materialism, and psych, exps., 297-9. 

Materia prima, 48, 231. 

Mathematics : and psych, of space, 
122-3 I validity of, 152-7 ; pleasure 
and, 243-6. See Measurements, 
mental ; Quantity. 

Matters, form, distinction approved, 
231. See Form, mental. 

Matter vs. Mind, see Mind and 
Body. 

Maudsley, 3. 

Measure, poetic, and rhythm of 
attention, 233-6. 

Measurements, mental: their pos- 
sibility, Ch. 111,33-65; importance 
of, 33 ; aim of, 37, 64; examples of, 
37-47; apparatus and methods of 
time measurements, 37-43 ; of in- 
tensity, 43-5 ; of space-discrimina- 
tion, 45-7; objections 10,34-5,47- 
65 ; is mind quantitative? 47-56 ; 
vs. physical, 56-7, 59 ; error of, 58, 
59 ; doubt about units of, 60-3. 

Mediumistic phenomena, as evidence 
for unconscious ideas, 76-9. 

Memory: for series of colors or 
forms, 28-9; as evidence for un- 
conscious, 70-6 ; does not imply 
preservation of ideas, 70-4; moral 
place of, 164, 193; and influence 
of time, Ch. IX, 165-184; vs. mere 



32 4 



Index 



return of idea, 165; analysis of, 
165-6, 190; field of exps. on, 166; 
Ebbinghaus's exps., 166-9; during 
short intervals, 169, 178 ; both blurs 
and distorts, 169-74; f° r different 
sense-materials, 170-1, 179-84; for 
forms, 171; memory-image, 172; 
clarification in, 174-9; corporate, 
174, 196; understanding in, 176; 
good m., 179; utility in, 180-1 ; 
temporal signs, 185-9; and the 
muses, 191 ; in personal develop- 
ment and identity, 189-94; vs - 
intelligent reproduction, 195-7 ; is a 
makeshift, 198 ; of angels, 198; mem- 
ories as acts, 305 ; a gratuity, 311. 

Metaphysics: relation to psych., 4; 
German weariness of, 7 ; and psych, 
methods, 19 ; and psych, of space, 
163-4; an d mental measurements, 
35; definition of the soul, 36, 271 ; 
and relation of mind and body, 
290-1 ; not assumed in psych, exps., 
296-9. 

Method, " eye and ear," 8. 

Method, in psych. : introspective, 1-4, 
17-18, 31, 86, 277 (see Introspec- 
tion) ; objective, 4, 31 ; physiolog- 
ical, 276-7 ; experimental, 1-16, 
17-34, 296-9. See Experiments, 
psychological. 

Metre : poetic, 233-5 '< as affected by 
mood and age, 255. 

Meumann, 268. 

Michelangelo, 254. 

Mill, James, 6. 

Mill, John Stuart, 6. 

Mind: subject to experiment, 17 (see 
Experiments, psychological) ; unity 
of, 119; activity of, 71, 119-21, 
163, 304; seems in presence of ob- 
ject, 123 ; organized from start, 
162; uselessness of, 282; views 
world indirectly, 123 ; worth of, in 
light of exps., 295 ; as analogous 
to physical things, 302-3 ; and soul, 
305-6 ; and body, see below. 

Mind and body : connection of, Ch. 
XIV, 262-94; undistinguished in 



early thought, 262; physical ex- 
pression of mental states, 263-71 
(see Expression) ; essential con- 
nection between, 270 ; disembodied 
mind, 270 ; interaction and paral- 
lelism, 278-91 ; more absorbing 
questions, 291-4 ; conclusion, 292- 
4 ; character of union not assumed 
in psych, exps. 296-8. 

Mind-reading, and involuntary move- 
ments, 205. 

Minimum visibile, 124-5. See Space- 
perception. 

Mirrors, projecting, exps. with, 147-9. 

Mob, action of, and suggestion, 217. 

Models of number-forms, 253. 

Molyneux's query, 128. 

Monday, symbol for, 252. 

Monism : and psychological quan- 
tity, 55 ; and relation of mind and 
body, 290-1. 

Montague, vi. 

Moral life, the : place of memory in, 
192-5; and imitation, 218; without 
a soul, 299; and associationisrn, 
303 ; and intellect, 308-9. 

Mosso, exps. on vascular reactions, 
265-8. 

Movement : in space-perception, 5-6, 
135-41 ; of the hand, 200-2 ; sway- 
ing of body, 203-4 ; attention and, 
203-5 1 involuntary m. and the 
occult, 205 ; passage of ideas into, 
206, 269 ; circulatory, 264-8 ; motor 
zone, 273. See Muscles. 

Miiller, G. E., 13. 

Miiller-Lyer illusion, 89. 

Munk, 274. 

Miinsterberg's illusion, 116. 

Muscles : in space-perception, 5-6 ; 
135-8 ; and psych, intensity, 50 ; in 
Ebbinghaus's exps. on memory, 
168; memory for impressions from, 
179-81 ; muscle-reading, 205 ; mus- 
cular theory of visual pleasure, 237- 
42 ; cerebral localization, 273-4. 

Music : Indians' recognition of, 134 ; 
disproves a theory of space, 159- 
60; defects in recognition of, 183; 



Index 



3*5 



pure tones in, 230 ; units of interest 
in, 235 ; pleasure in harmony, 243, 
246-7, 310-n; and mathematics, 
245 ; operatic, 256 ; separation of 
poetry from, 256-7; instrumental, 
257; its freedom from imitative 
restrictions, 258 ; " music " of color, 
259-60. 

Mutes, laughter of, 202. 

Mysticism : as escape from psychic 
quantity, 55 ; treats space lightly, 
164 ; of number, 246. 

Negative, photographic, and dis- 
turbed recognition, 132-3. 

Nerves: in reaction, 39-40; nerve- 
differences and space-discrimina- 
tion, 125-7; equivalence of neural 
and psychic processes, 285 ; psych., 
and primacy of, 292; nerve-cell 
pedagogy, 293. 

" New Theory of Vision," Berkeley's, 
4, 128. 

Nirvana, 66. 

Noble, exps. on literary rhythm, 

234-5- 

Novelty, not essential to value, 308. 

Number : the most pervasive of 
psych, quantities, 54-6; mysticism 
of, 246; number-forms, 253. See 
Measurements, mental; Quantity. 

Objective methods, 4, 31. 

Observation, and psych, exp., 297-8. 

Observatories, psych, in, 7-8. 

Omahas' recognition of music, 134. 

Opera, 256. 

Order : mind craves, 232 ; pleasure 
in, 240-1. 

Organic sensations, cerebral localiza- 
tion of, 274. 

Organization : mind probably pos- 
sesses, from start, 162; of expe- 
rience need not be spatial, 162. 

Oriental view : of the unconscious, 
66 ; of personality, 304. 

Originality : the basis of imitation, 
222-6; induced by others, 223-6. 

Ostwald, 286. 



Oyster, its freedom from illusions, 
108. 

Pain, organic changes connected 
with, 268. 

Painting : colors in old, 230 ; color 
in impressionist, 43, 249; rivalry 
of color and form in, 253-4 '. imita- 
tion in, 258. 

Parallel lines, illusions of, 53, 153-4. 

Parallelism, psycho-physical : mean- 
ing of, 278 ; and reflex action, 279 ; 
the crux of, 280 ; extravagance of, 
281, 284; vs. evolution, 281; 
means mutual uselessness of mind 
and body, 282; and philosophy, 
290-1 ; not necessary for psych, 
exps., 297-9. 

Paralysis : of ocular muscles, 135-6 ; 
and brain-lesions, 273-4. 

Paramecla, exps. on, 161. 

Passivity, of mind, apparent, 1 19-21. 

Paul, St., opposition to the " flesh," 
249. 

Pearson, K., 284. 

Pedagogy, nerve-cell, 293. 

Perception : and illusions, 104-5, 
108 ; involves fallacy, 109-10 ; min- 
gles good and evil, 116; Plato on, 
119-20; development of, 176-8; 
and parallelism, 280. 

Personal equation, 8, 38-43. 

Personality: alterations of, 70-1, 
75-6 ; dream-personalities and 
mediumship, 78 ; Oriental view of, 
304. See below. 

Persons : memory, and identity of, 
192-4; vs. books, 218-9; diff. of, 
regarding color and form, 251; 
and truth, 295-6 ; relation to psych, 
phen., 304-6; are the elemental 
realities, 306 ; psych, law and value 
of, 306-12. 

Perspective: motor factor in, 136-7; 
and the blind, 140. 

Pessimism, and the unconscious, 66. 

Phenomena, mental : cause of, 277, 
280, 287, 300-1 ; are not the mind, 
304-6, 314. 



326 



Index 



" Philosophical Transactions," 5. 

Philosophische Studien, 15. 

Philosophy, and psycho-physical the- 
ories, 290-1. See Metaphysics. 

" Phinuit," 76. 

Photography : of eye-movements, 
238-42 ; action of mind compared 
to, 287. 

Phrenology, 9, 272-5. 

Physics, vs. psych., 56-7. 

" Physiological Optics," Helmholtz's, 

9- 

"Physiological Psychology," Wundt's, 
14. 

Physiologists : influence upon psych., 
8 ; why pioneers, 17 ; attitude tow- 
ard mind, 277. See below. 

Physiology: no mastery of psych, 
without, 18 ; are psych, exps. but p. 
in disguise ? 20 ; psych, method in, 
22; value for psych., 276-7 ; physi- 
ological antecedents to every psych, 
event, 287; partiality toward, 293. 

Pierce, 142. 

Pineal gland, and the soul, 271-2. 

Piper, Mrs., automatisms of, 76. 

Pitch, memory for, 173. 

Platner: on memory, 72; visualist, 
139-40. 

Plato : unhappiness of tyrants, 35 ; 
sense-perception, 119-20 ; the sense- 
world, 249; mind and body, 270; 
evil, 293 ; aviary, 304. 

Pleasure: in sensations and their 
forms, Ch. XII, 227-48 ; causes of, 
in beauty, 247-8 ; in masterpieces 
of art, 228 ; color preference, 229- 
30; in tones, 230-1 ; in elementary 
forms, 232-45 ; rhythm, 232-6 ; 
curves, 237-40 ; in symmetry, 241 ; 
formal and intellectual vs. sensu- 
ous, 237-42, 254 ; in harmony, 243, 
310-n ; in proportion, 243-4 ; in 
number, 244-6; color vs. drawing, 
253; metrical effects, 255; and dif- 
ferentiation of arts, 256 ; modern 
vs. Greek attitude toward colorless 
form, 257 : organic changes with, 268. 

Plethysmograph, 264. 



Pluralism, and psych, quantity, 55. 
See Persons. 

Podmore, 92. 

Poetry : rhythm of, and of attention, 
233-6; auditory element in, 255; 
vs. music, 256. 

Points, illusion of three, 154. 

Polonius, as suggestible, 216. 

Professors, why not abolished, 218. 

Projection, of objects, 143-5. 

Proportion, pleasure in, 243-4. 

Protozoan, psych, of, 161-2. 

Psalms, 255, 271. 

Pseudoscope, 136, 140. 

" Psychical research," 66, 76-9. 

Psychologists' attitude toward brain 
and mind, 276, 277-8. See below. 

Psychology : " New," began in 
Greece, 1 ; its slow progress, 3 ; 
and metaphysics, 4, 19; indebted- 
ness to physiology, 18, 276-7 ; and 
the unconscious, 66-7, 93-4; its 
divisions artificial, 119; "without 
a soul," 299-306; and spiritual in- 
terests, 299-313. See Experiments, 
psychological ; Method, in psych. 

Psychometry, 37. See Measure- 
ments, mental. 

Psycho-physics : 11-13 ; relation of 
mind and body, Ch. XIV, 262-94. 

Pulpit, why not abolished, 218. 

Pulse, of consciousness, and aes- 
thetic pleasure, 233-6. 

Pulse, physiological, changes in, 
264-8. 

Pythagoras, remnants of his mysti- 
cism, 246. 

Quantity : importance in psych., 33 ; 
applicable to mind, 47-56; inten- 
sive, most troublesome in psych., 
48-51 ; spatial, not usually admitted, 
but should be, 51-3 ; temporal, may 
be neglected, but not by psychol- 
ogists, 54; numerical, pervades 
mind, 54-6; change of, in mem- 
ory, 170-1 ; quantitative correlation 
of mental and physical phen., 283- 
6. See Measurements, mental. 



Index 



327 



Questions, insistent, 211-12. 

Race, illusions of the, 158. 

Raehlmann's cases, 129, 131-2, 182. 

Rapport in hypnotism, 209. 

Ratio: the " golden," 243-4; mathe- 
matical, and pleasure, 243-6. 

Reaction : r. time and personal equa- 
tion, 8; exps. on, 38-43; of pro- 
tozoa, 161 ; physical expression of 
mental states, 263-71. 

Reality: as test of illusion, 111-12; 
character of real space, 155-7 ; 
social test of, 157; as interaction 
of experiences, 158. 

Reason, lords it over memory, 196- 
7. See Intellect. 

Recognition : in retention of series, 
29 ; r.-time, 41 ; affects sensations, 
101 ; in psych, of space, 131-5 ; by 
the blind, 129-32, 134-5 '> m photo- 
graphic negative, 132-2; with in- 
version, 133 ; Indians' r. of music, 
134; of music among cultivated 
persons, 183; in memory, 165-6; 
animals', 191-2. 

Recollection : nature of the process, 
71-5 ; vs. mere return, 165, or mere 
persistence of ideas, 190. See 
Memory. 

Rectangles, pleasure in, 243-4. 

Reflex-action, and parallelism, 279. 

Refreshment, in harmony, 246-7. 

" Reins," as seat of consciousness, 
271. 

Relations : important for harmony of 
senses, 150-1 ; obscured by inten- 
sity of sensations, 254-5. 

Relativity, in comparing sensations, 
11. 

Religion : imitation in, 219 ; exp. 
psych, and, 299-313. 

Rembrandt, 254. 

Reminiscence, and art, 191. See 
Memory. 

Respiration, and pleasure-pain, 268. 

Responsibility : imitation, hypnotism, 
and, 221-2; and psych, law, 306- 
12. 



Retina : rate of sensations from, 21- 
6; antagonism in, 97; in space- 
perception, 135-8 ; shifting parts of, 
138. 

Retinal-image : why unconscious of, 
143; size and inversion of, and 
space-perception, 142, 146-8. 

Rhyme, 255. 

Rhythm, enjoyment of, 232-6. 

Ring Cycle, Wagner's, 257. 

Rods and cones, and space-thresh- 
old, 126-7. 

Romantic ideal, 221. 

Royce, and imitation, 199, 206. 

Ruben, Johann, case of, 131-2. 

Rubens, 253. 

Ruskinian fidelity, violated by Na- 
ture, 152. 

Saborski, 178. 

Saints, their goodness available, 219. 

Sanford, v. 

Savages, color preferences of, 229-30. 

Scholastic distinction of matter and 
form, 231. 

Schulze, exps. on blind, etc., 46. 

Science : and evidence, 93-4 ; vs. 
memory, 195-6; cannot cheapen 
life, 311. 

Scripture, E. W., v, 205. 

Sculpture: 228; interest in, 254; 
colored, 257. 

Seat of consciousness, 271-5. 

Secretiveness, seat of, 274. 

Section, golden, 243-4. 

Selection, in imitation, 223. 

Self-consciousness, and imitation, 
218. 

Self-observation, see Introspection. 

Sensations: Weber's Law, 11; in 
neural research, 22 ; imperceptible 
differences in, 26; psych, exp. not 
confined to, 27-30; intensity of, 
48-51; faint s. seem alike, 87; 
imperceptible, 88-90 ; influenced 
by surroundings, 101 ; are neither 
true nor false, 106; interpretation 
of, 104, 112-14, 117 ; not enough for 
truth, 114 ; require our activity, 



328 



Index 



120; simultaneity vs. extension, 
159; as inherently extended, 160- 
3; "pure," 161-2; supplemented, 
177, 190, 213; durability of, 180; 
different relative value of, 180-3; 
modified by suggestion, 214-16; 
enjoyment of, Ch. XII, 227-48; 
as origin of mind, 303 ; as acts of 
mind, 305 ; cerebral localization of, 
274-6. See Color ; Music ; Smell ; 
Sound; Touch. 
" Sensations of Tone," Helmholtz's, 

9- 

Sense-organs: in psych, exps., 27-30; 
in illusion, 96-8, 106-8 ; and space- 
threshold, 125. 

Senses : evidence of, and reality, 158 ; 
ranking of, 179-80; order of de- 
velopment, 275. See Sensations. 

Series: memory for, 28-9; mental 
forms of, 252-3. 

Shadows : color of, 43, 214 ; space- 
judgment, and imperceptible, 88- 
90. 

Shakespeare : rhymed couplets, 255 ; 
quoted, 216, 270. 

Shinn, 229. 

Shop-window exp. in suggestion, 216. 

Shorthand, natural law as, 284. 

Sidis, on hypnotism, 210. 

Sight: frequency of sensations of, 
21-6; a compound sense, 135; 
memory for, 179-80 ; and smell in 
dog, 183 ; variation of importance, 
183-4; cerebral localization of, 
274; dependent upon other senses, 
274-5; m infancy, 275. See be- 
low. 

Sight in space-perception : 5-6, 
124-5; * ts ran k vs. touch, 127-41; 
as originally non-spatial, 134; 
retina vs. muscles, 135-8 ; har- 
mony with touch, 143-51 ; discords 
with touch, 151-2. See Color; 
Blind. 

Signal-system, space-perception as, 
123, 126-7. 

Size, in sight and touch, 150-2, 154. 

Skin, transplanting of, 138. 



Sleep: sensations in, 97; effect of 
calling name in, 267. See 
Dreams. 

Smell: in animals, 183; in infants, 
275 ; cerebral localization of, 274. 

Society: social test of reality, 157; 
corporate memory of, 196 ; social- 
ism in psych., 157, 221; and in- 
dividual, 226, 303-4 ; social reform 
and physiology, 293. 

Socrates, and relation of soul and 
body, 291-2. 

Solomons, on interaction, 288. 

Sophie Charlotte and Leibnitz, 68-9. 

Sophocles vs. Wagner, 257. 

Soul : simplicity of, and psych, quan- 
tity, 36 ; seat of, 271-6 ; worth and 
reality of, 295-314; "psych, with- 
out a soul," 299-306; in psych, 
explanation, 300-2; sense-impres- 
sions and, 305 ; mind and, 305-6. 

Sound : not a compound, yet quanti- 
tative, 48; threshold of, 79; con- 
fused with pressure, 87 ; subliminal, 
90-1; illusory intensity of, 98-9; 
complication of color and, 99-100 ; 
memory for, 170-1, 173-4, 179-80 ; 
in foreign tongue, 47, 213; subjec- 
tive grouping, 232; colored, 252; 
emotional character of, 259 ; cere- 
bral localization of, 274; without 
power to interpret, 275. See 
Music. 

Space: spatial quantity in psych., 
51-3; recognition hindered, 131-5; 
"real" s., and illusions, 155-7; 
idealization, 156-7; and music, 
160; psych, beginnings of, 160-3; 
extension vs. simultaneity, 159; 
not indispensable, 162; place of, 
in mental life, 164; memory for, 
171; pleasure in form, 237-44; in- 
terest in, vs. color, 251-2; space- 
thinking, 252. See below. 

Space-perception : rank of senses in, 
5-6, 127-141 ; Berkeley on, 4-6, 
128-31; threshold 0^45-7, 124-5; 
and imperceptible shadows, 88-90 ; 
exps. on, particularly of blind, 



Index 



329 



Ch. VII, 122-141 ; Kantian vs. 
British view of, 122; and modern 
geometry, 122, 152; localization 
in, 122-7; visualists vs. tactualists, 
128-41 ; of the blind, 129-35 ; 
retina vs. eye-muscles in, 135-8 ; 
pseudoscope, 136 ; stereoscope, 
137 ; telestereoscope, 137 ; shifting 
parts of skin and retina, 138; of 
touch and sight: their harmonies, 
142-51, and discords, 151-2; non- 
Euclidean, 152-7 ; of protozoans, 
161-3 ; and time-perception, 187-8 ; 
vs. color-perception, 250. 

Speech, automatic, 76-9. 

Spencer, 6, 122. 

Sphygmograph, 264. 

Spiral, revolving, 97. 

Spirit, disembodied, mental poverty 
of, 270. 

Spiritistic view of automatisms, 77. 

Spiritual, the: vs. the sensuous in 
art, 249 ; primacy of, undetermined, 
292; implications of exp. work, 
Ch. XV, 295-314; and common 
psych, phen., 305-6. See Soul. 

Spurzheim, 9. 

Stars, angular discrimination of, 124. 

Stentor, exps. on, 161. 

Stereoscope, 102, 137. 

Stevenson, 70. 

Stoic ideal, 221. 

Stout, 74. 

Stowell, A., exps. on blind, etc., 46. 

Subconscious: phen., 69, 80; ratios, 
245. See Unconscious. 

Subliminal ; s. stimuli, and s. sen- 
sations, 79-81 ; s. sensations, prob- 
able, 86-88 ; interruptions noticed, 
90-1. See Unconscious. 

Suggestion: and imitation, Ch. XI, 
199-226; at bottom the same as 
imitation and hypnotism, 209 ; post- 
hypnotic, 211; physical effects of, 
212; in sense-perception, 213; 
modifies sensations, 214-16; in 
touch, 214; brief exposures, 215; 
determines preference, 216-17 ! 
effect of, on character, 217-8 ; two 



aspects of, 220 ; hindered by vivid- 
ness of impressions, 254-5. See 
Hypnotism ; Imitation. 

Sully, on logic of illusion, 108-11. 

Superposition, illusion of, 154. 

Surgeons : their exps. on congeni- 
tally blind, 5-6, 129-135; trans- 
planting skin, 138. 

Surprise : enjoyment of, 239, 248 ; in 
life, 308-9. 

Symbols, spatial, 252-3. 

Symmetry, pleasure in, 241-2. 

Sympathy, in pleasure in lines, 239-40. 

Symphony, 61, 257. 

System of experience, as test of il- 
lusion, 112-14. 

Table-tipping, 205. 

Tabula rasa doctrine, 119. 

Tactile impressions, see Touch. 

" Tactile Values," 214. 

Tactualists' theory, 128-41. 

Tapestries, color of, 230. 

Tarde, and imitation, 199. 

Tasters of wine and tea, 175. 

Tawney, on suggestion, 214. 

Teaching: psych, of memory, and, 
184; imitation in, 218; and nerve 
physiology, 293. See Children. 

Telestereoscope, 136-7. 

Temperature, mistaken for pressure, 
87. 

Tennyson, 120. 

Terza rima, of Dante, 255. 

Test : of illusion, 108-15 '> social and 
individual t. of reality, 157-8. 

Testimony, personal t. and senses, 
215. 

Thecetetus: sense-perception, 119- 
120; view of mind, 304. 

Theology, and psych, quantity, 55. 

Thoughts, by machinery, 262. 

Thought-transference, 205, 304. 

Threshold: meaning of, 79; for all 
senses, 83-4; absolute vs. dis- 
criminative, 86-7. 

Time: early exps., 9 ; localization in 
a series, 28-9 ; temporal quantity 
in psych., 54; and imperceptible 



33o 



Index 



phen., 85; illusions of, 99; and the 
blind, 139-40; not linear, 160 ; an 
ultimate process, 164; memory 
and the influence of, Ch. IX, 165- 
84; mind in and outside of, 166; 
rate of forgetting, 166-9 i temporal 
signs, 185-9; factors in t.-judg- 
ments, 186-9; temporal fore- 
ground, 187. 

Titchener : v ; on reaction-time, 41-42. 

Tones : imperceptible stimuli, 79-81 ; 
threshold of, 83, 175; memory, 
x 73i z 7^ > preference, 230 ; har- 
mony, 245. See Music. 

Torrey, vi. 

Touch : Weber's exps., 10-11 ; in 
blind and normal persons, 45-7, 
181 ; threshold, 61, 84-5 ; confused 
with sound and warmth, 87 ; rank 
of, as space sense, 5-6, 127-41 ; in 
vision, 135-7 ; impressions of, why 
not projected, 143; harmony with 
sight as regards distance, 143-5, 
direction, 145-9, size, 150-1 ; dis- 
cords with sight, 151-2; memory 
for, 179-80, 181; cerebral localiza- 
tion of, 273 ; in infancy, 275. 

Tradition, as corporate memory, 196. 

" Transcendental ^Esthetic," Kant's, 

155- 
Transplanting skin, 138. 
Tree, and psych, quantity, 48-9. 
Trinchinetti's cases, 130. 
Trinitarianism, and psychic quantity, 

55- 
Tristan und Isolde, 66. 
Truth : prejudiced by its sponsors, 

93; personal consequences of, 

295-6. 
Tschisch, von, on memory, 173, 179. 
Tuke, Hack, 212. 
Tuning-fork, tone of, 230, 248. 

Ugliness, and eye-movements, 239- 

40. 
Unconscious, the : evidence for, Chs. 

IV, V, 66-94; bearings of problem, 

66-8 ; seems self-contradictory, 68 ; 

Leibnitz and, 68-9; alterations of 



personality, 70-1; memory and 

hypnotism, 70-6; automatic com- 
munications, 76-9 ; subliminal 
stimuli, 79-81; more favorable 
evidence, 82-91; u. ideas vs. u. 
materials for ideas, 83-94; proba- 
bility of u. sensations, 88 ; extreme 
views, 92-3 ; conclusion, 92-4. 

Understanding, in memory, 176; in 
time-judgments, 188-9; m enjoy- 
ment, 188-9, 2 48 ; takes life out of 
sensations, 254. See Intellect. 

Uniformity of mind, 306-7. 

Unitarianism and psychic quantity, 
55- 

Unity: of mind, impressed by il- 
lusions, 119; unity in variety, in 
aesthetics, 249. 

Upright vision, 146-9. 

Utility: and fading of sensations, 
180-1 ; in evolution, 281 ; vs. par- 
allelism, 281 ; of mind for the body, 
292. 

Vagueness : of mental phen., 56; in 
color-contrast, 58. 

Value : mental scales of, 194-5 ! °f 
life, and surprise, 308. 

Vase, eye-movements, in viewing, 242. 

Veneration, seat of, 273. 

Ventricles, cerebral, as seat of soul, 
272. 

Verbal associations, and memory, 
29. 

Verse: rhythm, 233-6; metrical ef- 
fects, 255. 

Vierordt, and time-sense, 9. 

Violin, tone of, 248. 

Virgil, quoted, 269. 

Vision, see Sight. 

Visualists' theory, 128-41. 

Voice, 181, 231. 

Volitional pleasure in lines, 239-40. 

Voluminousness, as inherent in sen- 
sations, 160-3. 

Vorticella, exps. on, 161. 

Wagner, 66, 257. 
Wallin, on rhythm, 236* 



Index 



33 1 



Ward : on extension of sensations, 
160-3 ; on mind and body, 291. 

Wardrop, 5. 

Ware, 5. 

Warmth, confused with pressure, 87. 

Weber : in history of psych, exps., 
10-13 1 l aw °f discrimination, 10- 
ii, 285; and Lotze, 15. 

A/'ednesday, symbol for, 252. 

Weights, perception of, see Touch. 

Weight-size illusion, 98. 

Wernicke, region of, 274. 

Whispering, involuntary, 206. 

Wilkinson, 46. 

Will : an ultimate mental fact, 164 ; 



and competition of ideas, 207 ; in 
enjoyment of lines, 239-40. 

Williams, 9. 

" Will to Believe," James's, 211. 

Women, preference for red, 230. 

Wonder, and science, 311. 

" Wonderland," Alice's, 107. 

Worlds, without illusions, 107. 

Writing, automatic, 76-9. 

Wundt, vi. 5, 20'; rank and influ- 
ence, 14-15 ; choroiditis, 138. 

Zollner's illusion, 52-3. 
Zoneff, 268. 



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